Drug Interaction
When one drug changes the way, another drug works in the body.
The interaction between 5-HTP and antidepressant medication has not been studied in any great detail. Still, it’s best to err on the side of caution and consult with a doctor if you’re considering taking 5-HTP while on such medications.
5-HTP is an amino acid that increases serotonin levels in the brain by promoting the production of the neurotransmitter, and some antidepressant drugs work by increasing brain levels of this same chemical (SSRIs).
Some people who take SSRIs report feeling increased anxiety when taking 5-HTP. This could be because they are using too high a dose or haven’t allowed their bodies to adjust before adding 5-HTP to their medication regimen.
5-HTP can increase serotonin levels in the brain just as antidepressant medications do, so there is a risk of an adverse reaction after adding 5-HTP to your SSRI regimen.
5-Hydroxytryptophan (5-HTP) is rapidly decarboxylated to serotonin (5-hydroxytryptamine or 5-HT), therefore exerting physiologic effects similar to that of L-tryptophan, a precursor of 5-HT.
This evidence suggests that ingestion of supplemental tryptophan or 5-HTP may potentially pose similar risks associated with elevated blood serotonin levels. In addition, the presence of other supplements or medications that raise serotonin levels may enhance these risks.
During the last few years, a new class of drugs has become available for depression. They are called selective serotonin reuptake inhibitors or SSRIs. These medicines work by increasing the activity of a chemical messenger in the brain called serotonin. Unfortunately, some people experience unwanted side effects from SSRIs. Therefore, it is generally recommended that 5-HTP not be combined with an SSRI.
Warnings:
If you’re taking any medications, check with your doctor before starting 5-HTP supplements. Likewise, do not take 5-HTP if you’re pregnant or breastfeeding without first checking with your physician.
As stated above, some researchers suggest that women on SSRI antidepressants should avoid using 5-HTP. In addition, 5-HTP should not be combined with any medication that increases serotonin levels in the brain.
This includes antidepressants, pain medications, migraine treatments, cough syrup containing dextromethorphan (cough medicine), and certain over-the-counter weight loss pills. If you’re taking a blood thinner or have a bleeding disorder, check with your doctor before beginning a regimen of 5-HTP supplements.
People who take SSRIs to treat depression may risk “serotonin syndrome” if they take other drugs that increase serotonin levels in the brain. This condition may include shivering, diarrhea, nausea and vomiting, insomnia, rapid heart rate, and increased body temperature.
Types of drug interactions:
1. Pharmacodynamic interactions:
drugs may interact in a way that is harmful to the patient. This type of interaction results from a mechanism affecting the effect of a drug or vice versa. The interaction may be beneficial or adverse/toxic.
An example of a pharmacodynamic interaction would be the combined administration of a β blocker and a non-selective NSAID causing severe bradycardia, hypotension, and hypoperfusion due to additive peripheral vasoconstriction caused by each drug individually.
2. Pharmacokinetic interactions:
Drugs can interact at any stage, and the body’s ability to absorb, metabolize and excrete drugs to alter levels in blood plasma causes toxicity or lack of efficacy. This type of interaction may be intentional, as in reducing adverse or unwanted effects of a drug by another drug that affects hepatic enzyme activity responsible for metabolizing the first drug.
An example is the ability of macrolide antibiotics to prolong the half-life of cyclosporin medicine (used in transplant to prevent rejection), increasing the risk of toxicity due to high plasma levels. Another example is when grapefruit juice inhibits intestinal epoxide hydrolase, an enzyme responsible for breaking down many drugs, causing abnormally high concentrations and effects in the body.
4. Pharmacological interactions:
drugs can interact specifically with other medicines via their pharmacodynamic or pharmacokinetic properties, as described above. However, some medicines may also interact pharmacologically, i.e., via their chemical structures. The classic example of this is the drug interaction with mixing opioids and monoamine oxidase inhibitors (MAOIs). MAOIs inhibit the metabolic degradation of tyramine found in cheese, beer, wine, and other foods.
When MAOIs are combined with certain opioids, the hypertensive crisis can result from excessive accumulation of this substance. This type of drug interaction explains the somewhat reduced analgesic effect seen when some opioid analgesics (such as morphine) are given together with an inhibitor of peroxidase enzymes known as “N-acetyltransferase,” commonly referred to simply as “N-acetyl.”
5. Pharmacogenetic interactions:
Pharmacogenetics can be defined as studying inherited genetic differences that give rise to differing responses to drugs. One example is the congenital deficiency in metabolizing enzymes responsible for breaking down a pill by normal metabolism, resulting in poor metabolism and clearance of a drug from the body after administration. This leads to an accumulation of the drug, which may cause or worsen adverse effects.
Another example involves individuals with a genetic deficiency in their ability to produce normal levels of stomach acid. As a result, these people are more prone to gastric ulcers when treated with non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen.
6. Pharmacokinetic interactions:
drugs can interact at any stage along with the body’s ability to absorb, metabolize and excrete drugs to alter levels in blood plasma, causing toxicity or lack of efficacy. This type of interaction may be intentional, as in reducing adverse or unwanted effects of a drug by another drug that affects hepatic enzyme activity responsible for metabolizing the first drug.
An example is the ability of macrolide antibiotics to prolong the half-life of cyclosporin medicine (used in transplant to prevent rejection), increasing the risk of toxicity due to high plasma levels. Another example is when grapefruit juice inhibits intestinal epoxide hydrolase, an enzyme responsible for breaking down many drugs, causing abnormally high concentrations and effects in the body.
7. Pharmacological interactions:
drugs can interact specifically with other medicines via their pharmacodynamic or pharmacokinetic properties, as described above. However, some medications may also interact pharmacologically, i.e., via their chemical structures. The classic example of this is the drug interaction with mixing opioids and monoamine oxidase inhibitors (MAOIs). MAOIs inhibit the metabolic degradation of tyramine found in cheese, beer, wine, and other foods.
When MAOIs are combined with certain opioids, the hypertensive crisis can result from excessive accumulation of this substance. This type of drug interaction explains the somewhat reduced analgesic effect seen when some opioid analgesics (such as morphine) are given together with an inhibitor of peroxidase enzymes known as “N-acetyltransferase,” commonly referred to simply as “N-acetyl.”
8. Pharmacogenetic interactions:
Pharmacogenetics can be defined as studying inherited genetic differences that give rise to differing responses to drugs. One example is the congenital deficiency in metabolizing enzymes responsible for breaking down a pill by normal metabolism, resulting in poor metabolism and clearance of a drug from the body after administration.
This leads to an accumulation of the drug, which may cause or worsen adverse effects. Another example involves individuals with a genetic deficiency in their ability to produce normal levels of stomach acid. As a result, these people are more prone to gastric ulcers when treated with non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen.
9. Pharmacokinetic interactions:
drugs can interact at any stage along with the body’s ability to absorb, metabolize and excrete drugs to alter levels in blood plasma, causing toxicity or lack of efficacy. This type of interaction may be intentional, as in reducing adverse or unwanted effects of a drug by another drug that affects hepatic enzyme activity responsible for metabolizing the first drug.
An example is the ability of macrolide antibiotics to prolong the half-life of cyclosporin medicine (used in transplant to prevent rejection), increasing the risk of toxicity due to high plasma levels.
Another example is when grapefruit juice inhibits intestinal epoxide hydrolase, an enzyme responsible for breaking down many drugs, causing abnormally high concentrations and effects in the body.
10. Pharmacological interactions:
drugs can interact specifically with other medicines via their pharmacodynamic or pharmacokinetic properties, as described above. However, some medications may also interact pharmacologically, i.e., via their chemical structures.
The classic example of this is the drug interaction with mixing opioids and monoamine oxidase inhibitors (MAOIs). MAOIs inhibit the metabolic degradation of tyramine found in cheese, beer, wine, and other foods.
When MAOIs are combined with certain opioids, the hypertensive crisis can result from excessive accumulation of this substance. This type of drug interaction explains the somewhat reduced analgesic effect seen when some opioid analgesics (such as morphine) are given together with an inhibitor of peroxidase enzymes known as “N-acetyltransferase,” commonly referred to simply as “N-acetyl.”