Read Feeling Good: The New Mood Therapy Online
Authors: David D. Burns
If your blood pressure goes up to a dangerous level, you should call your doctor or go to an emergency room. How much elevation is dangerous? The blood pressure consists of two numbers. The higher number is called the “systolic” blood pressure and the lower number is called the “diastolic” blood pressure. A value of 120/80, for example, would be considered normal for most people. Most emergency room doctors would not be particularly concerned until these numbers reach the range of 190 to 200 over 105 to 110. At that level, they might observe you carefully and monitor your blood pressure every few minutes. Most of
the time, the elevated blood pressure will subside without treatment. If your blood pressure continues to rise, the ER doctor could give you an antidote (such as phentolamine or prazosin) to lower your blood pressure back into a safe range.
The best time to take your blood pressure is about one to one and a half hours after you have taken the medication. About 25 percent of my patients have noted modest blood pressure elevations at this time even if they have not eaten any of the forbidden foods in Table 20–8 on pages 580–581 or taken the medicines in Table 20–9 on pages 584–590. These increases were not usually extreme or dangerous—a 20- or 30-point elevation in the systolic blood pressure was typical. Nevertheless, in those cases, I have recommended stopping the medication because these patients seemed overly sensitive to the effects of the MAOI on their blood pressure. It just did not seem worth the worry and risk, especially since a different antidepressant might be just as effective.
Foods to Avoid
. Hypertensive crises may occur if you eat foods (see Table 20–8) that contain a substance known as tyramine. If you are taking an MAOI, too much tyramine can interfere with your brain’s ability to regulate your blood pressure. Tyramine causes nerves to release more norepinephrine into the synaptic regions that separate them from the postsynaptic nerves. These postsynaptic nerves may become overly stimulated when too much norepinephrine is released. Because these nerves help to regulate blood pressure, all the extra norepinephrine that is released can cause a dangerous and sudden increase in blood pressure.
You will recall from Chapter 17 that an enzyme called monoamine oxidase (MAO) is located inside the presynaptic nerves. This enzyme usually destroys any excess norepinephrine that builds up inside these nerves and prevents these nerves from releasing too much norepinephrine when they fire. But the MAOI drugs block this enzyme, and so the norepinephrine levels inside these nerves increase substantially. When you eat foods containing tyramine, all that extra norepinephrine suddenly spills into the synaptic region, causing a massive stimulation of the nerves that regulate your blood pressure.
Table 20–8.
Foods and Beverages to Avoid If You Are Taking a Monoamine Oxidase Inhibitor (MAOI)
a
Foods to Avoid Completely |
Cheese, particularly strong or aged cheese (cottage cheese and cream cheese are allowed) Beer and ale: particularly tap beers, beers from microbreweries and strong ales Red wine: especially Chianti wine Brewer’s yeast tablets or yeast extracts (breads and cooked forms of yeast are safe. The yeast extracts from health food stores are dangerous. Yeast extracts may be found in certain soups. Some powdered protein diet supplements contain yeast extracts.) Pods of fava beans, also called Italian green beans (regular green beans are safe) |
Meat or fish that is smoked, dried, fermented, unrefrigerated, or spoiled, including: • fermented or air-dried sausages, such as salami and mortadella (some experts state that bologna, pepperoni, summer sausage, corned beef, and liverwurst are safe) • pickled or salted herring • liver (beef or chicken), especially old chicken liver (fresh chicken liver is safe) Overripe bananas or avocados (most fruits are completely safe) Sauerkraut Some soups, including those made from beef bouillon or Asian soup stocks (e.g., miso soup). (Tinned and packet soups are felt to be safe, unless made from bouillon or meat extracts) |
Foods or Beverages that May Cause Problems in Large Amounts |
White wine or clear alcohol, such as vodka or gin Sour cream Yogurt: must be pasteurized and less than 5 days old to be safe Soy sauce NutraSweet (the artificial sweetener) Chocolate Caffeine in beverages (coffee, tea, and soda) and chocolate |
Foods or Beverages Once Thought to Cause Problems which Are Probably Safe in Small Amounts |
Figs (avoid overripe figs) Meat tenderizers Caviar, snails, tinned fish, pate Raisins |
a
Modified from B. McCabe and M. T. Tsuang, “Dietary Considerations in MAO Inhibitor Regimens,”
Journal of Clinical Psychiatry
43 (1982): 178–181.
If you watch your diet carefully, the likelihood is good that you will experience no adverse blood-pressure elevation. The most common trigger is cheese, especially strong cheese. You will have to give up pizza and grilled cheese sandwiches for a while if you are taking an MAOI.
Most of the forbidden foods contain the breakdown products of protein—including tyramine. So, for example, freshly cooked chicken is perfectly safe, but cooked leftover chicken that has been sitting for a couple days can be dangerous because tyramine forms when the meat decomposes. One of my patients on tranylcypromine (Parnate) ate some leftover chicken that had been in the refrigerator for several days. Soon after eating it, he experienced a significant elevation in blood pressure. This was because the chicken had partially decomposed due to effects of bacteria. Fortunately, he was not harmed, but this experience served as a useful warning to be careful. The fermented or partially decomposed meats on the list in Table 20–8, such as strong sausage or smoked fish, as well as strong cheese, may contain large amounts of tyramine and can be especially dangerous. Some experts also advise against eating Chinese food while taking MAOIs. This may be due to the soy sauce, the monosodium glutamate, or other ingredients.
How much tyramine is necessary to cause a hypertensive reaction? This varies quite a bit from person to person. On
average, foods containing at least 10 mg of tyramine will be sufficient to cause a hypertensive crisis if you are taking phenelzine (Nardil). As little as 5 mg of tyramine may be sufficient if you are taking tranylcypromine (Parnate). What foods contain this amount of tyramine? Well, most beers contain less than 1.5 mg of tyramine, and many contain less than 1 mg, so you would have to drink several beers to run a significant risk. However, some ales contain 3 mg of tyramine per serving, and some tap beers can also be particularly risky. For example, one serving of Kronen-bourg, Rotterdam’s Lager, Rotterdam’s Pilsner, or Upper Canadian Lager contains between 9 and 38 mg of tyramine
17
. So even one glass of these beers could be dangerous.
Cheeses can also vary greatly. Processed American cheese contains only about 1 mg of tyramine per serving, but Liederkranz, New York State cheddar, English Stilton, blue cheese, Swiss cheese, aged white cheese and Camembert all contain more than 10 mg per single serving.
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Suppose you eat one of the forbidden foods by accident, and then you check your blood pressure and discover that it does not go up. What does this mean? There is a lot of individual variation in the sensitivity to the effects of the forbidden foods. You may be one of those individuals who is significantly less likely to react with an elevation in blood pressure. However, you should not become complacent, because these hypertensive reactions are unpredictable. If you cheat and eat the forbidden foods from time to time, it is a lot like playing Russian roulette. You may get away with it for a while and then discover that you have experimented once too often. For example, you may eat a piece of pizza on nine separate occasions without any increase in blood pressure, and conclude that it is safe to eat pizza. But this can be very misleading, because the tenth time you eat a piece of pizza you may experience a sudden and severe increase in blood pressure. It is not known why this happens, but it does underscore the importance of consistent self-discipline if you are taking an MAOI.
Medications and Drugs to Avoid
. A number of prescription drugs, nonprescription drugs, and street drugs that can cause a hypertensive or hyperpyretic crisis when combined with MAOIs are listed in Table 20–9 on pages 584–590. These reactions are especially dangerous and so you must carefully avoid these drugs. Some of the medications that interact with MAOIs do not cause such severe reactions. For example, caffeine may cause you to become more jumpy and jittery than usual. Moderate amounts of caffeine are reasonably safe, however. (You may think of caffeine as more of a food than a drug, but it is a mild stimulant.)
The list of drugs that interact with MAOIs includes:
• most antidepressants—virtually any of them can be dangerous;
• many antiasthma drugs;
• many common cold, cough allergy, sinus, decongestant, and hay fever medications that contain sympathomimetic agents (discussed in detail below) or dextromethorphan, the cough suppressant. You will have to check labels carefully, because many over-the-counter drugs contain these substances;
• drugs used in the treatment of diabetes—they may become more potent than usual if you are taking an MAOI, and can cause your blood sugar to fall more than expected;
• some drugs used in the treatment of low or high blood pressure—both types of drugs can in some cases cause blood pressure elevations when combined with MAOIs;
• mood stabilizers and anticonvulsants;
• some painkillers, including some local and general anesthetics;
• sedatives (including alcohol) and tranquilizers—they may have more pronounced effects than usual when you are taking an MAOI. The increased sleepiness could be hazardous if you are driving;
• L-tryptophan—the natural amino acid;
• stimulants (pep pills) and street drugs;
• many weight-loss (appetite suppressing) medications;
• caffeine, which is present in coffee, tea, many sodas, hot cocoa, and chocolate. Caffeine is also present in a number of prescription and nonprescription medications such as Cafergot suppositories and tablets, Darvon Compound-65, NōDōz, Fiorinal, Excedrin, and many other cold or pain preparations;
• Disulfiram (Antabuse), used to treat alcoholism;
• Levo-dopa, used in the treatment of Parkinson’s disease.
Table 20–9.
Prescription Drugs and Over-the-Counter Medications to Avoid If You Are Taking a Monoamine Oxidase Inhibitor (MAOI)
a
Note: | |
Antidepressants | |
Drug | Comment |
tricyclic antidepressants | Some (e.g., clomipramine) may cause a hyperpyretic crisis or seizures; others (e.g. desipramine) may cause a hypertensive crisis |
tetracyclic antidepressants | hypertensive crisis (noradrenergic syndrome) |
SSRIs | hyperpyretic crisis (serotonin syndrome) |
other MAOIs | hyperpyretic crisis (serotonin syndrome); hypertensive crisis (nonadrenergic syndrome) |
serotonin antagonists | hyperpyretic crisis (serotonin syndrome) |
mirtazapine | hypertensive crisis (noradrenergic syndrome) |
venlafaxine | hypertensive crisis (noradrenergic syndrome) |
Asthma Medicines | |
Drug | Comment |
ephedrine | hypertensive crisis |
inhalants | blood pressure elevations and a rapid heart; beclomethasone and other nonsystemic steroid inhalers are generally safer |
theophylline (Theo-Dur) | rapid heart and anxiety |
Cold, Cough, Allergy, Sinus, Decongestant, and Hay Fever Medications (including tablets, drops, or sprays) | |
Drug | Comment |
antihistamines: | can cause an increase in MAOI blood levels |
dextromethorphan | hyperpyretic crisis (serotonin syndrome); may also cause brief episodes of psychosis or bizarre behavior |
ephedrine | hypertensive crisis (noradrenergic syndrome) |
oxymetazoline (Afrin) | hypertensive crisis (noradrenergic syndrome) |
phenylephrine | hypertensive crisis (noradrenergic syndrome) |
phenylpropanolamine | hypertensive crisis (noradrenergic syndrome) |
pseudoephedrine | hypertensive crisis (noradrenergic synarome) |
Diabetes Medications | |
Drug | Comment |
insulin | may cause a greater drop in blood sugar |
oral hypoglycemic agents | as above |
Medications for Low Blood Pressure (for patients in shock) | |
Drug | Comment |
sympathomimetic amines • dopamine (Intropin) • epinephrine (Adrenalin) • isoproterenol (Isuprel) • metaraminol (Aramine) • methyldopa (Aldomet) • norepinephrine (Levophed) | hypertensive crisis (noradrenergic syndrome) because these drugs cause blood vessels to constrict |
Medications for High Blood Pressure | |
Drug | Comment |
guanadrel (Hylorel) guanethidine (Ismelin) hydralazine (Apresoline) methyldopa (Aldomet) reserpine (Serpasil) | These blood-pressure medications may cause a paradoxical increase in blood pressure when combined with MAOIs. |
beta-blockers | may be more potent when combined with MAOIs, leading to a greater-than-expected drop in blood pressure and dizziness when standing |
calcium channel blockers | appear to be reasonably safe when combined with MAOIs. Check with your doctor and monitor blood pressure closely. Watch for a greater-than-expected drop in blood pressure |
diuretics | watch for a greater-than-expected drop in blood pressure. May increase blood level of MAOI |
Mood Stabilizers | |
Drug | Comment |
carbamazepine (Tegretol) | hyperpyretic crisis (serotonin syndrome); MAOI may cause carbamazepine levels to fall, so epileptics may experience seizures |
lithium (Eskalith) | can cause hyperpyretic crisis (serotonin syndrome) in animal studies |
Painkillers and Anesthetics | |
Drug | Comment |
anesthetics: general | Tell your anesthesiologist you are on an MAOI. If possible, discontinue the MAOI two weeks before elective surgery |
| Muscle relaxants such as succinylcholine and tubocurarine may have a more pronounced or prolonged effect. General anesthetics such as halothane may lead to excitement, excessive depression of the brain, or hyperpyretic reactions |
anesthetics: local | Some contain epinephrine or other sympathomimetics—make sure you tell your dentist you are taking an MAOI |
Pain Medications and Anesthetics cont. | |
Drug | Comment |
cyclobenzaprine (Flexeril) | hyperpyretic crisis (serotonin syndrome) or severe seizures |
meperidine (Demerol) | A single injection can cause seizures, coma, and death (serotonin syndrome). Most other narcotics, including morphine and codeine, have been used safely with MAOIs |
Sedatives and Tranquilizers | |
Drug | Comment |
alcohol | May have enhanced sedative effects, especially when combined with phenelzine (Nardil). This could be hazardous when driving or operating dangerous machinery |
barbiturates | enhanced sedative effects as described above |
buspirone (BuSpar) | enhanced sedative effects as described above |
major tranquilizers | enhanced sedative effects as described above; some neuroleptics may cause a drop in blood pressure when combined with MAOIs |
minor tranquilizers | enhanced sedative effects as described above |
sleeping pills | enhanced sedative effects as described above |
L-tryptophan | hyperpyretic crisis (serotonin syndrome); blood pressure elevations; disorientation, memory impairment, and other neurologic changes |
Stimulants (Pep Pills) and Street Drugs | |
Drug | Comment |
amphetamines cocaine benzedrine benzphetamine (Didrex) dextroamphetamine (Dexedrine) methamphetamine (Desoxyn) methylphenidate (Ritalin) | the hypertensive crisis (noradrenergic syndrome) is possible; methylphenidate is considered somewhat less risky than the amphetamines |
Weight-Loss and Appetite-Suppression Medications | |
Drug | Comment |
pemoline (Cylert) | drug interactions have not been studied in humans; great caution should be used; some experts report that pemoline has been combined with MAOIs in some cases |
fenfluramine (Pondimin) | hyperpyretic crisis (serotonin syndrome) |
phendimetrazine (Plegine) | hypertensive crisis (noradrenergic syndrome) |
phentermine and some over-the-counter meds | hypertensive crisis (noradrenergic syndrome) |
phenylpropanolamine (Acutrim) | hypertensive crisis (noradrenergic syndrome) |
stimulants | hypertensive crisis (noradrenergic syndrome) |
Other MAOI Drug Interactions | |
Drug | Comment |
caffeine | Probably safe in moderate amounts; avoid large amounts; may cause blood pressure elevations, a racing heart, and anxiety |
disulfiram (Antabuse) | Severe reactions when mixed with an MAOI |
L-dopa (Sinemet) | hypertensive crisis (noradrenergic syndrome) |