Pollen is one of the most common causes of allergies in the United States (US).
About 8% of adults and children in the US have pollen allergies.
Worldwide, 10-30% of the population is affected by this condition.
Pollen is a powdery substance that is transported from one plant to another to help in fertilization (reproduction). Pollen is made up of minute pollen grains.
Plants release pollen grains in the atmosphere, and these either travel through the wind or are carried by birds, animals, and insects to other plants. Light, dry, and small pollen grains can easily travel by the wind. Pollen grains are the most common causes of allergies.
Pollen allergy can be seasonal or year long. It is usually seen in most people during the growing seasons and depends on the specific pollen that you’re allergic to. During spring, there’s tree pollen in the air that some people are allergic to. Others may be allergic to grass pollen, especially during summer. Ragweed allergies usually occur in late spring or early fall.
Once pollen enters the human body, the immune system of people allergic to pollen considers it as a foreign and dangerous substance. The immunoglobulin E (IgE) cells are antibodies that are produced by the immune system in the presence of an allergen. When pollen comes in contact with IgE cells in the tissues of the nose and mouth, the tissues release chemicals like histamine and leukotrienes to alert the body.
Known for their peculiar barks that peel like paper, birch trees are found throughout the cool regions of Northern hemisphere.
Birch trees are wind pollinated. The levels of pollen are influenced by many factors including the weather, local flora diversity, etc. A single birch tree can produce up to 5 million pollen grains.
Oral Allergy Syndrome or OAS is a form of a contact allergic reaction triggered due to the consumption of certain raw fruits and vegetables. This is because your immune system mistakes the proteins present in these for pollen due to their similarity.
Some foods that cross-react with birch pollen allergy are:
These chemicals cause the body to respond with unpleasant allergic symptoms, including:
- Sneezing
- Itch in the nose, eyes, mouth, and ears
- Runny nose
- Excess mucus production in the nose
- Itchy throat
- Coughing
- Wheezing
There are thousands of different species of trees, plants, bushes, and shrubs that release pollen into the atmosphere. Some people can be allergic to a certain type of pollen but be alright when exposed to other types.
Here are some of the common types of pollen allergies found in the United States.
1. Grass pollen allergy
2. Ragweed pollen allergy
3. Oak pollen allergy
4. Cedar pollen allergy
Changes or mutations in certain genes have been observed in people with birch pollen allergy. Studying these changes can help predict if a person has a higher risk for these allergies as compared to other people.
The CHI3L1 gene contains instructions for producing Chitinase-3-like protein 1, a glycoprotein. Glycoproteins are molecules that consist of a carbohydrate and protein.
CHI3L1 proteins are involved in both innate and adaptive immune responses.
Any changes in this gene can result in exaggerated immune responses to harmless substances found in environment, like tree pollens.
rs880633
rs880633 one such change (or Single Nucleotide Polymorphism - SNP) found in the CHI3L1 gene.
People who carry the G allele for this SNP are at an increased risk for birch pollen allergy than those with the C allele.
Season - Late winter and spring seasons are when the pollen count in the atmosphere is very high. People experience pollen allergies the most during these seasons.
Climate changes - When plants produce more pollen, the pollen count in the atmosphere is high, and this increases the chances of pollen allergy flare-ups. Here are factors that affect pollen production.
- Air temperature
- CO2 (Carbon dioxide) in the atmosphere
- Intensity of sunlight
- Rainfall
Insect migration - The number of insects that carry pollen from one place to another has increased globally. Insects are migrating from one place to another in large numbers. This also increases the chance of getting allergies.
Increase in global humidity - Increase in humidity makes insects, dust mites, and molds more active. This, in turn, increases exposure to pollens.
External irritants - External irritants like aerosol spray, tobacco smoke, dust mites, wood smoke, and air pollution exposure can also trigger hay fever by making the nasal passage more sensitive to irritants.
A pollen allergy can usually be diagnosed easily, but you may need to consult an allergist sometimes to confirm the reaction and treat it.
Skin-prick test: A small amount of allergen is pricked into different areas of the skin. After 15-20 minutes, if signs of allergy like redness, swelling, and itchiness are observed, the person is said to be allergic to pollen.
The best way to manage any allergy is to avoid the allergen causing it. This can prevent severe allergic reactions.
Avoiding exposure:
- Try to stay indoors on windy days.
- Wear a mask when pollen counts are reported to be high.
- Try to avoid gardening or yard work during peak growing season.
Home remedies:
- Vacuum your house regularly using a vacuum with HEPA filters to eliminate any allergens.
- Wash clothes that you wear outside as pollen may stick to them.
- Try to avoid drying clothes outside as pollen may stick to them.
- Keep a squeeze bottle handy in case you inhale pollen and need to flush it out of your nose.
- Use air conditioning at home and in the car to avoid direct exposure to pollen.
Medications:
Certain OTC medications like antihistamines and decongestants can help with allergy symptoms.
Allergy shots:
If OTC medications don’t help with symptoms, your doctor would recommend an allergy shot.
Allergy shots are basically a series of injections containing the allergen. The shots are meant to help your immune system get used to the allergen and reduce the severity of symptoms. A series of shots is needed overtime to help relieve symptoms.
Food Allergies:
Most people mistake OAS for food allergies and restrict the consumption of only those foods. It is important to get checked for OAS and avoid all the trigger foods.
https://www.healthline.com/health/allergies/pollen
https://acaai.org/allergies/types-allergies/pollen-allergy
https://www.medicalnewstoday.com/articles/322256
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5157985/
Have you ever felt dizzy on a car or train ride? This sensation of wooziness is called motion sickness. This usually occurs when you’re in repeated motion in a vehicle or any other movement that can affect your inner ear and balance.
Repeated motion tends to mess up the balance of the body. The sensory organs receive different signals. For example, when you’re in an airplane, your body may feel the minor turbulences, but your eyes see a stationary view, and this is conflicting. The different sensory receptors send mixed signals to the brain, and this causes motion sickness.
Humans have a functional vestibular system that is responsible for the balance. The sensory systems in your body include the inner ear, eyes, skin pressure receptors, muscle and joint sensory receptors. The inner ear contains motion-sensing organs. It is an important contributing factor to motion sickness.
People with motion sickness can usually diagnose themselves when they travel or do other specific activities that involve a lot of movement. The symptoms wear off after the travel, usually. In rarely severe cases, professional help may be required.
Common symptoms of motion sickness include:
- Nausea
- Vomiting
- Stomach upset
- Dizziness
- Loss of balance
- Sweating
- Headache
- Drowsiness
Variations in certain genes have been observed in people with motion sickness. Studying these variations can help predict if a person has a higher risk of motion sickness compared to other people.
The GPD2 gene encodes an enzyme involved in glucose homeostasis (maintenance of blood glucose levels). The enzyme is called glycerol-3-phosphate dehydrogenase 2.
rs56051278
rs56051278 is an SNP found in the GPD2 gene. The minor allele, the G allele, is found to be associated with an increased risk of motion sickness.
The PRDM16 gene encodes a protein called PR Domain containing 16. This protein is also called a zinc finger transcription factor. It is involved in the development of brown adipose tissue, also called brown fat. The main function of brown fat is to turn food into body heat.
rs61759167
rs61759167 is an SNP found in the PRDM16 gene. The minor allele, the T allele, is found to be associated with an increased risk of motion sickness.
Following the recommendations mentioned below, can help avoid motion sickness while travelling:
- In a car, try to open a window for some fresh air every once in a while.
- Avoid reading books during travel.
- Close your eyes and relax or try napping.
- Driving yourself or sitting in the front can help relieve symptoms.
- Get plenty of rest the night before traveling and eat a few hours ahead so that your stomach is settled.
- Avoid greasy, spicy, or acidic food before travel.
- Chewing fresh ginger or in a tablet form can help deal with symptoms.
- Chewing, in general, is found to help with conflicts between vision and balance. Chewing gum is a common way to deal with motion sickness symptoms.
- Peppermint has soothing effects on the body and helps you relax.
- Breathing exercises and acupuncture are found to help people.
Medications
If home remedies don’t help you deal with symptoms completely, certain medications can be taken. These are usually prescribed by a doctor. These medications include:
- Scopolamine: It is the most commonly prescribed medication. It is in the form of a patch that is placed behind the ear 6-8 hours before travel.
- Promethazine: The effects last for about 6-8 hours and the medicine should be taken 2 hours before travel. There are side effects like dry mouth and drowsiness.
- Cyclizine: This medication needs to be taken 30 minutes before travel.
- Dimenhydrinate chewing gum: This medication available in the form of chewing gum is absorbed through the cheek.
- Meclizine: This is not recommended for children below 12 years of age. This needs to be taken 1 hour before travel for the maximum effect.
https://www.healthline.com/health/motion-sickness
https://www.medicalnewstoday.com/articles/176198
https://www.webmd.com/cold-and-flu/ear-infection/motion-sickness#1
https://www.ncbi.nlm.nih.gov/pubmed/25628336
Histamine Intolerance is the excess accumulation of histamine in the body. About 1% of the world’s population is diagnosed with histamine intolerance.
Histamine is an organic compound produced in the body. It is also obtained from certain foods you eat. Histamine has the following functions in the body:
- Releases stomach acid to help digestion
- Informs the brain in case of inflammation or allergy
- Helps in the contraction of smooth muscles of the stomach, lungs, and uterus
- Dilates blood vessels and reduces blood pressure
- Increases heart rate in case of physical or mental trauma or danger
Below are the symptoms of excess histamine accumulation in the body:
- Diarrhea
- Irritable Bowel Syndrome (IBS)
- Stomach pain and cramps
- Itchy skin and hives
- Congested or runny nose
- Itchy, watery, and red eyes
- Continuous sneezing and coughing
- Dizziness
- Rapid heart rate and high blood pressure
- Difficulty in breathing
It is almost too easy to mistake the symptoms of histamine intolerance for those of a food allergy. This is because in both cases, the symptoms are a result of a surge in histamine levels. However, the reason for this surge is different in each case.
In food allergies, proteins in certain foods are seen as invaders, and our immune system releases histamine and other chemicals. These, in turn, cause symptoms like itching and hives.
In histamine intolerance, the symptoms are brought about by histamine-rich foods or foods that induce the excess release of histamine. Histamine intolerance is not sensitivity to histamine but an indication that too much of it has built up in your body. This occurs when your body cannot break down histamine effectively. Depending on the breakdown rate, different individuals can tolerate different levels of histamine.
The amine oxidase copper containing 1 (AOC1) gene produces diamine oxidase (DAO) in the body. DAO helps breakdown histamine. Lowered levels of DAO leads to higher levels of histamine in the body.
Certain mutations in the AOC1 gene results in histamine intolerance. Certain SNPs in the AOC1 gene results in decreased DAO levels, thereby increasing the risk of histamine intolerance:
When you are intolerant to histamine, it does not mean you are sensitive or allergic to histamine. It only means that your body has accumulated more histamine than what’s usually needed.
Bacterial infections - Bacterial infections lead to bacteria overgrowth in the body, and this can increase histamine levels. Normal levels of DAO cannot breakdown this excess histamine.
Excessive consumption of histamine-rich foods - Fermented foods, canned foods, alcohol, smoked meat, pickles, etc., are very high in histamine levels. Including these foods in your everyday diet can increase histamine accumulation in the body and lead to histamine intolerance.
Foods encouraging histamine release - While some foods can be low in histamine, they can encourage the release of histamine from the tissue mast cells. Few such food options that can lead to histamine intolerance are:
- Citrus fruits
- Papaya
- Berries
- Tomatoes
- Pineapple
- Nuts
- Chocolate
- Egg white
- Pork
- Fish
- Crustaceans like crabs, lobsters, and shrimps
Certain drugs and long term medications - Certain drugs are known to increase histamine production in the body. Long term use of such medications can lead to histamine intolerance.
If you are taking one or more of the below drugs, talk to your doctor about their effects on your histamine levels.
- Antibiotics
- Antidepressants
- Diuretics
- Muscle relaxants
- Tuberculosis medications
- Antipsychotics
Atopic eczema - Studies show that people with severe atopic eczema end up having higher histamine levels in the plasma. This can, with time, lead to histamine intolerance.
Excess alcohol consumption - When you consume excess alcohol, it leads to histamine intolerance in the following ways:
1. Alcohol and histamine metabolic pathways release the same enzymes - aldehyde oxidase. This prevents histamine from getting fully broken down.
2. Alcohol encourages the tissue mast cells to release more histamine than what’s needed.
3. Alcohol reduces DAO production in the body leading to increased histamine levels. This can result in histamine intolerance.
Diamine Oxidase (DAO) supplements - A 2019 study made use of DAO oral supplements in people with histamine intolerance. The study concluded that the symptoms of the condition reduced greatly with these supplements.
Histamine-elimination diet - Check the list of foods rich in histamine and eliminate them from your diet for at least 2-3 weeks. This is enough to eliminate stored histamine from the body. Start adding one food at a time and watch for the reappearance of the symptoms. This will help create your own food plan that keeps the symptoms of histamine intolerance controlled.
Choose fresher foods - Most packaged, canned, frozen, and pickled foods are high in histamine levels. You can control the symptoms when you choose fresher fruits, vegetables, greens, and grains.
Know your threshold for alcohol - Some people with severe histamine intolerance start stowing symptoms with very little alcohol in the body. Others can handle a certain limit before they reach their threshold. Drink moderately and watch your body for allergic flare-ups. You will know your alcohol limit over time.
https://www.medicalnewstoday.com/articles/322543#symptoms
https://www.entandallergy.com/blog-posts/details/your-mystery-food-sensitivity-might-actually-be-a-histamine-intolerance
https://pubmed.ncbi.nlm.nih.gov/17490952/
https://www.histamineintolerance.org.uk/about/the-food-diary/the-food-list/
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1398-9995.2011.02548.x
https://pubmed.ncbi.nlm.nih.gov/21488903/
Adefovir is a medication used to treat people with chronic hepatitis B infection. This belongs to a group of drugs called nucleotide analogs.
Nucleotide analogs represent a major class of antiviral drugs.
This is an oral pill that has to be taken regularly for a specific period of time.
It is prescribed for adults and children older than 12.
It is commonly sold under the brand name Hepsera.
Adefovir works by blocking an enzyme called reverse transcriptase in the body.
The Hepatitis B Virus (HBV) needs this enzyme to replicate in the body.
By blocking the enzyme, the drug can prevent the virus from multiplying and growing in the body.
This drug cannot cure hepatitis B or protect from its side effects.
It may also not be effective in preventing the spread of the disease from the infected person to others.
Adefovir only reduces the viral load.
Some common side effects of adefovir are:
Some of the more severe side effects of adefovir are:
Some people rarely develop allergic reactions to adefovir.
Contact your doctor if you experience any allergic symptoms after consuming the drug.
Allergic symptoms include the below:
Adefovir can interact with many other drugs and can lead to serious side effects or reduced efficacy of the drugs.
Consult your doctor if you take one or more of the below medications:
Once it reaches the body, adefovir is not cleared by the Cytochrome P450 enzymes like most drugs.
The drug also does not bind to the plasma or serum proteins. Instead, it is cleared by the kidneys.
The SLC22A6 gene (solute carrier family 22 member 6) contains instructions for the production of the SLC22A6 protein, also called the Human Organic Anion Transporter 1 (hOAT1) protein.
This protein is found in the proximal tubular cells of the kidneys. It plays a role in the clearance of drugs like adefovir by taking them to the kidneys.
Changes in the SLC22A6 gene can lead to over-exposure of the kidneys to the adefovir drug and may cause renal toxicity.
rs11568634 is a Single Nucleotide Polymorphism (SNP) in the SLC22A6 gene.
People with the CC genotype of this SNP may have increased uptake of adefovir dipivoxil compared to those with the CT and TT genotypes.
| Genotype | Implications |
| CC | Increased uptake of adefovir dipivoxil |
| CT | Normal uptake of adefovir dipivoxil |
| TT | Normal uptake of adefovir dipivoxil |
Adefovir blocks nucleic acid synthesis in the body.
Nucleic acid is a molecule found in all cells and viruses and includes DNA and RNA.
As a result, the OAT1 proteins are not able to effectively eliminate the drug from the body.
This leads to drug buildup in the proximal tubule cells of the kidneys.
This buildup damages these cells and can lead to renal impairment, leading to antiviral-induced Fanconi syndrome.
Changes in the SLC22A6 gene increase the risk of this problem.
Though rare, studies show that this is a possibility that doctors should monitor in patients treated with adefovir or other antiviral medications.
People who discontinue the medication without instructions from a doctor can experience life-threatening symptoms, including death.
Do not discontinue or change drug dosages without consulting your doctor.
Adefovir overdose can lead to kidney problems, seizures, and unconsciousness.
Call emergency medical services right away if you suspect an overdose of the drug.
People who have had prior liver transplant surgeries or other liver disorders may experience renal failures, and their conditions have to be monitored regularly.
A study analyzed the effect of adefovir in 467 individuals with pre and post-liver transplant surgeries.
According to the study, 4% of patients had to discontinue adefovir because of adverse side effects.
Genetic testing will help understand the impact of adefovir on the kidneys and help plan dosages better.
Analyze Your Genetic Response to Adefovir
https://www.pharmgkb.org/pathway/PA155028030/pathway
https://www.webmd.com/drugs/2/drug-64164/adefovir-oral/details
https://www.rxlist.com/hepsera-drug.htm#P
https://medlineplus.gov/druginfo/meds/a605024.html
https://www.rxwiki.com/adefovir#overdose
https://www.medicinenet.com/adefovir_dipivoxil-oral/article.htm#Overdose
https://pubmed.ncbi.nlm.nih.gov/18276803/
https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/slc22a1
Adalimumab is a drug used to treat autoimmune disorders like rheumatoid arthritis, Crohn’s disease, and ulcerative colitis. This drug is sold under brand names like Humira, Amgevita, and Cyltezo.
Adalimumab is available in liquid form and needs to be injected under the skin.
Adalimumab belongs to a group of medications called Tumor Necrosis Factor (TNF) inhibitors. TNF inhibitors suppress the actions of the Tumor Necrosis Factor, which is a small protein that plays a role in the inflammatory response by the immune system.
The immune system is overactive and produces an excess of TNF in people with autoimmune diseases. This leads to inflammation and pain in the body. By suppressing TNF, adalimumab prevents inflammation and its unpleasant effects.
When taken without proper guidance from a doctor, Adalimumab can increase the risk of infections in the body, including tuberculosis, and even lead to death.
Other common side effects of the drug are:
Some serious side effects of Adalimumab are:
Adalimumab can interact with other drugs used to treat autoimmune diseases and cause severe side effects.
Some commonly used drugs to treat autoimmune conditions and their symptoms are:
The HFE gene (homeostatic iron regulator gene) helps produce the HFE protein. This protein is present in the liver, intestines, and immune cells. It helps control how much iron is absorbed from food and stored in the body.
Studies show that the effect of TNF inhibitors in treating autoimmune diseases varies depending on changes in the HFE gene.
rs2071303 is a Single Nucleotide Polymorphism (SNP) in the HFE gene. People with the G allele of this SNP seem to respond better to Adalimumab when compared to people with the A allele.
| Allele | Implications |
| G | Better response to Adalimumab |
| A | Normal response to Adalimumab |
The ATG16L1 gene (autophagy-related 16 like 1 gene) helps regulate autophagy. Autophagy is a process that the cells use to recycle their worn-out parts and break down unwanted proteins. It also plays a role in the body’s inflammatory response.
rs10210302 is an SNP in the ATG16L1 gene. People with Inflammatory Bowel Disease (IBD) carrying the risk allele T were significantly more prone to use Adalimumab when compared to those with the C allele.
| Allele | Implications |
| T | People with Inflammatory Bowel Disease (IBD) were more prone to use Adalimumab |
| C | People with Inflammatory Bowel Disease (IBD) had normal usage of Adalimumab |
The TRAF1 gene (TNF receptor-associated factor 1 gene) plays a role in the survival of cells and cell death (apoptosis).
People with the GG genotype of the TRAF1 (+16860A/G) SNP had lowered levels of clinical response to anti-TNF treatments compared to those with the AG or AA genotypes.
Lowered levels of clinical response to drugs like adalimumab may reduce the effectiveness of the treatment. Such individuals may have to take additional dosages for the medicine to work.
Make sure to notify your doctor of your existing health conditions:
Adalimumab, when taken along with other autoimmune drugs, can create extreme side effects. Talk to your doctor about your current medications in advance.
Adalimumab may increase the risk of infections. If your child is receiving this drug, make sure your child has received all appropriate vaccinations.
Genetic testing will help understand a person’s response to adalimumab, including how much of the drug the body accepts and how quickly the drug is eliminated from the body. This will make dosage planning more effective and prevent drug toxicity too.
Analyze Your Genetic Response to Adalimumab
https://en.wikipedia.org/wiki/Adalimumab
https://www.nhs.uk/medicines/adalimumab/
https://medlineplus.gov/druginfo/meds/a603010.html
https://www.nhs.uk/medicines/adalimumab/
https://www.humira.com/global/frequently-asked-questions
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4296073/
https://www.rxlist.com/consumer_adalimumab_humira_amjevita/drugs-condition.htm
https://www.drugs.com/drug-interactions/adalimumab,humira.html
Codeine is a drug used to treat mild or moderate pain in the body. It is a natural plant extract derived from opium.
Opium is a latex extract of the Papaver somniferum (opium poppy) plant and contains about 12% morphine.
Morphine is a chemical that affects the Central Nervous System (CNS) and alters pain sensations.
Codeine is available as pills, capsules, or oral solutions.
This drug is a part of the 2021 World Health Organization’s (WHO’s) Essential Medicines List.
Codeine is an opioid drug used to relieve moderate pain and cough.
It is commonly used in combination with Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) or acetaminophen (a drug to treat fever and pain).
Opioid drugs act on the opioid receptors, a part of the opioid system that regulates pain, addictive behaviors, and rewards.
Upon interaction, they bring down the ability of the body to feel the pain.
Codeine can be used to treat chronic pain resulting from a medical condition or injury.
It is also prescribed after surgery for post-surgical pain.
It is also given in case of chronic pain that regular painkillers cannot treat.
Codeine is added to certain drugs that treat chronic cough and diarrhea.
No, codeine is not an anti-inflammatory drug.
It is, however, often used in combination with NSAIDs to improve its efficacy.
Codeine belongs to the narcotic analgesics and antitussives class of medications.
Narcotic analgesics change the way the body experiences pain, and antitussives are drugs that prevent coughing.
Codeine is converted into morphine in the liver.
Morphine now attaches itself to the opioid receptor in the CNS.
The CNS regulates pain sensations.
Morphine prevents the neurotransmitters from sending pain signals to the brain, hence lowering the intensity of pain.
Image: How codeine works in the body
Tramadol is another similar opioid pain killer, but this is manufactured industrially and not extracted from natural substances like codeine.
Both these pain killers are equally effective. However, studies show that tramadol may have a slightly increased risk of all-cause mortality compared to codeine.
Some of the common side effects of codeine are:
Some of the more severe side effects of codeine are:
In most cases, codeine can be detected in the urine for up to 48 hours after using the drug.
In long-term codeine users, the drug can be detected in the urine for up to one week.
In a small study, a group of 10 volunteers consumed eight doses each of a cough syrup containing 4.5 mg of codeine phosphate.
The study reported that codeine was present in the urine samples for 30 hours after the last dose.
Codeine can interact with other drugs and lead to changes in drug efficacies or worsen the side effects. Notify your doctor if you are on any of the following drugs:
Yes. Ibuprofen, an NSAID, can be taken along with codeine.
Studies show that a combination of these drugs acts as a very effective analgesic and can help handle post-operative pain.
However, you can take ibuprofen with codeine only after consulting a qualified medical practitioner.
The CYP2D6 gene provides instructions for producing the Cytochrome P450 2D6 enzyme.
This enzyme is expressed in the liver and helps metabolize more than 25% of all prescription drugs, including codeine.
It converts codeine into its active form - morphine.
CYP2D6 gene has more than 100 star alleles.
Star alleles are used to name different haplotypes. A haplotype is a group of gene changes that are inherited together.
| Alleles (CYP2D6) | Functioning |
| *1, *2, *27, *33 | Normal-function alleles |
| *10, *17, *41, *49 | Decreased-function alleles |
| *3, *4, *5, *6, *36 | Non-function alleles |
Normal functioning alleles produce normal levels of the CYP2D6 enzyme with optimal activity.
Decreased functioning alleles produce lower levels of the CYP2D6 enzyme with lowered activity.
Non-functioning alleles do not produce any enzyme.
There are three kinds of CYP2D6 metabolizers identified depending on the combination of alleles they have.
| Metabolizers | Genotype | Implications |
| Ultrarapid | Have more than 2 copies of the normal-function alleles | Increased enzyme activity and high risk of toxicity |
| Normal | Have 1 normal-function and 1 decreased-function alleles or 2 normal-function alleles | Normal enzyme activity and no additional risk of codeine toxicity |
| Intermediate | Have 1 decreased-function and 1 no-function alleles or 2 decreased-function alleles or 1 normal-function and 1 no-function alleles | Intermediate enzyme activity and slightly reduced morphine levels |
| Poor | Have 2 no-function alleles | No enzyme activity and significantly reduced morphine levels |
The opioid receptor mu 1 gene (OPRM1 gene) provides instructions for producing the mu-opioid receptor.
This receptor controls the opioid system and is the primary target area for codeine and other opioid medicines.
rs1799971 is a Single Nucleotide Polymorphism (SNP) in the OPRM1 gene.
A 2015 meta-analysis studied different OPRM1 gene changes and their effects on opioid drug usage in a study sample of 5902 students.
The results revealed that people with the G allele of this SNP had to consume more opioid drugs than people with the A allele but still ended up with higher pain levels.
| Allele | Implications |
| G | Consumed more opioid drugs to experience analgesia, yet reported higher pain |
| A | Normal doses of opioid drugs resulted in effective analgesia |
Some people may have allergic reactions to codeine and experience breathlessness, hives, itching, and swelling immediately after consuming the drug.
If you face any discomfort, rush to your nearest Emergency Room or dial 911.
Since codeine is an opioid drug and contains about 12% morphine, it can increase the risk of drug dependence, especially with prolonged use.
People with the following conditions have a higher chance of overusing the drug and getting dependent on it.
If you think you are overusing the drug, contact your doctor immediately.
In 2017, the Food and Drug Administration (FDA) restricted the use of codeine in children.
According to FDA, codeine may cause life-threatening conditions, including breathlessness and death in individuals younger than 18.
Since one of the side effects of codeine is breathing difficulties, it needs to be used very cautiously in people with existing respiratory conditions.
A study analyzed the relationship between codeine usage during pregnancy and fetal harm in 7640 pregnant mothers.
According to the study, the risk of major birth defects was 4.9% with codeine usage (which is not different from the general population risk).
However, codeine usage in pregnancy can cause a condition called neonatal withdrawal in newborns.
Neonatal withdrawal or Neonatal Opioid Withdrawal Syndrome (NOWS) is a condition where the infant, being exposed to opioid drugs in the womb, is suddenly deprived of the same after delivery and goes through severe withdrawal symptoms.
The symptoms may include:
NOWS is a severe condition and can turn life-threatening too.
Infants of women who are treated with opioid drugs in the last trimester have a higher chance of experiencing NOWS.
Is Codeine Safe In Pregnancy?
Minimal amounts of the drug taken for short periods during early pregnancy may be safe if the benefits outweigh the risk and no alternate pain medications can be used.
Your doctor will be able to take a call about this.
Codeine overuse and use during the last trimester may lead to a serious infant condition called Neonatal Opioid Withdrawal Syndrome (NOWS).
Codeine may be expressed in breast milk and may expose your baby to morphine, leading to the following side effects in the infant.
Talk to your doctor if you are breastfeeding and are on codeine.
Genetic testing may help understand if a person will need higher, normal, or lower doses of codeine to achieve the expected analgesic effects.
This can prevent the risk of overdoses and make the treatment process more effective.
Analyze Your Genetic Response to Codeine
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6540848/
https://www.nhs.uk/medicines/ibuprofen-and-codeine-nurofen-plus/
https://pubmed.ncbi.nlm.nih.gov/12201569/
https://www.statpearls.com/ArticleLibrary/viewarticle/25271
https://www.nhs.uk/medicines/codeine/
https://en.wikipedia.org/wiki/Morphine
https://reference.medscape.com/drug/codeine-343310#3 https://medlineplus.gov/druginfo/meds/a682065.html
http://apps.who.int/iris/handle/10665/325771
https://en.wikipedia.org/wiki/Codeine#Mechanism_of_action
https://www.drugs.com/codeine.html#interactions
https://pubchem.ncbi.nlm.nih.gov/compound/Codeine
Know Your Response To Drug Therapies Using Your 23andMe, AncestryDNA Raw Data!
