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The subject of drug-food interactions is vast and complicated. In this series of articles we only take a look at those interactions that may occur between certain foods and drugs used to treat psychiatric or psychological conditions (i.e. antidepressants, anxiolytics, lithium, MAO-inhibitors and anticonvulsants).
Basic principles
Chemical compounds used in pharmacological preparations can have many different effects on food and nutrient absorption. Conversely, certain foods may react with certain drugs to produce undesirable effects.
Decreased dietary intake
Certain psychotropic drugs are known to depress the appetite and may cause the patient to eat less food, which in turn can lead to malnutrition and/or deficiency diseases. Ritalin is well-known for depressing appetite in young children and causing growth impairment.
This is the reason why it is so important to have all children who receive Ritalin closely monitored by a Child Psychiatrist, who will check that the child is experiencing normal growth. Growth failure and/or retardation are indications for stopping medication with Ritalin, but always discuss such a step with the prescribing doctor.
The following drugs, which are used to treat psychiatric conditions, may depress the appetite:
* Temazepam, fluphenazine, carbamazepine
Other psychotropic medications may change or reduce taste sensations, thus resulting in reduced food intake and inadequate nutrition. Examples of such drugs are:
* Flurazepam, lithium carbonate, phenytoin, triazolam
Serotoninergic drugs, which inhibit the uptake of serotonin, produce feelings of increased satiation thus reducing food intake.
Warning: Never take psychotropic drugs, intended for the treatment of psychiatric and psychological conditions, for the purpose of weight reduction. This is a perverse use of medications that can have serious effects on your psychological makeup and overall health.
Drugs that increase appetite
A number of medications used to treat psychiatric conditions such as depression, anxiety, and epilepsy, can increase appetite, thus leading to overeating and weight gain.
The following are examples of appetite-stimulating psychotropic drugs:
* Anticonvulsants, such as carbamazepine and valproic acid
* Sedatives or antidepressants, such as chlordiazepoxide (Librium), diazepam (Valium), chlorpromazine hydrochloride, meprobamate, amitriptyline hydrochloride, trifluoperazine
If you are receiving antidepressants, anticonvulsants or other psychotropic medication and notice that your appetite has increased and/or that you are gaining weight, please discuss this with the prescribing doctor as it may be necessary to either adjust your dose or change the medication.
Monoamine oxidase inhibitors
Monoamine oxidase inhibitors (MOAIs) are known to react with the so-called pressor amines that occur quite commonly in many foods. The vasoactive or pressor amines, such as tyramine, serotonin and histamines found in foods and beverages, are usually rapidly metabolised by two enzymes, monoamine and diamine oxidase.
For this reasons, they are not normally associated with adverse effects such as constriction of blood vessels and increased blood pressure, or associated symptoms such as irregular heartbeat, chest pains and severe headache in humans.
However, when a patient is taking MOAIs (found in antidepressants, antimicrobial, antihypertensive and antineoplastic drugs), the action of these two enzymes is blocked and pressor amines in foods and beverages may produce the above-mentioned symptoms.
In severe cases unmetabolised pressor amines can cause brain haemorrhage, heart arrhythmias and heart failure. It is in the best interest of the patient to avoid food and drinks rich in pressor amines when they are taking MOAIs.
Food and beverages rich in pressor amines: (Adapted from Krause, 2000)
Avoid totally: All types of cheese, smoked or pickled fish, liver, aged meat, biltong, Chianti and Vermouth, broad beans, meat extracts, yeast extracts and brewer’s yeast, dried sausage (droëwors), sauerkraut, beer and ale.
Eat cautiously: Avocado, raspberries, soy sauce, chocolate, red and white wine, port, spirits (gin, brandy, cane, whiskey), peanuts, and yoghurt and cream made of unpasteurised milk.
Food that may contain pressor amines, but have not yet been identified conclusively (if you notice any symptoms after eating these foods, cut them out of your diet):
Fresh fish, mushrooms, cucumber, sweet corn, fresh pineapple (canned pineapple is allowed), Worcestershire sauce, salad dressings, bread baked with yeast, raisins, tomato juice, curry powder, beetroot, boiled eggs, Coca Cola, biscuits, cottage and cream cheese.
Patients who are being treated with MOAIs need to consult a clinical dietician to assist them in avoiding foods that can trigger potentially fatal reactions.
It is evident that psychotropic drugs can have pronounced effects on appetite, food intake, growth, weight gain or loss, and balanced nutrition. Conversely, food and beverages that contain pressor amines can have a dramatic effect on health when drugs such as the MOAIs are prescribed.
Therefore, if you are taking antidepressants, anxiolytics, lithium, MAO-inhibitors, or anticonvulsants, it is essential that you firstly read the package insert to check for effects on food intake and nutrient balance, and secondly that you discuss potential drug-food interactions with the prescribing doctor.
If your psychotropic medication is depressing your appetite, causing weight gain, or if it includes MOAIs, you should also consult a clinical dietician to help you combat these effects. – (Dr I.V. van Heerden, DietDoc)
Please note: There are several new medications that will be added to this article soon. Watch this space. If you have any questions in the meantime, please consult Health24's DietDoc and Cybershrink.
