Feeling Good: The New Mood Therapy (74 page)

^a
Information in this table was obtained from several sources including the
Manual of Clinical Psychopharmacology
¹
and
Psychotropic Drugs Fast Facts
.
¹⁷
These excellent references are highly recommended.

^b
Many patients have been successfully treated with a combination of an MAOI and a tricyclic antidepressant under close observation, but such drug combinations are dangerous and require a high level of expert supervision.

Drugs that are categorized as sympathomimetics are particularly dangerous because they are contained in many over-the-counter drugs for common ailments such as colds. They are called sympathomimetics because they tend to mimic the effects of the sympathetic nervous system, which is involved in the control of blood pressure.

Several sympathomimetic drugs are found in large numbers of prescription and over-the-counter cold preparations, cough medicines, decongestants, and hay fever medications. These include ephedrine, phenylephrine, phenylpropanolamine and pseudoephedrine. For example,
ephedrine
can be found in Bronkaid, Primatene, Vicks’ Vatronol nose drops, and several other cold and asthma medications.
Phenylephrine
can be found in Dimetane, Dristan decongestants, Neo-Synephrine nasal spray and nose drops, and many other similar preparations.
Phenylpropanolamine
is contained in Alka-Seltzer Plus Cold Medicines, Contac decongestants, Coricidin D decongestants, Dexatrim appetite suppressant pills, Dimetane-DC Cough syrup, Ornade Spansules, Robitussin-CF, Sinarest, St. Joseph Cold Tablets, and many other cold medicines.
Pseudoephedrine
can
be found in Actifed, Advil Cold & Sinus, Allerest No-Drowsiness formula, Benadryl combinations, Dimetane-DX Cough syrup, Dristan Cold Maximum Strength, Robitussin-DAC syrup, Robitussin-PE, Seldane-D tablets, Sinarest No Drowsiness, Sinutab, Sudafed, Triaminic Nite Light, and numerous Tylenol allergy, sinus, flu, and cold preparations, as well as several Vicks products including NyQuil, to mention just a few.

Some cold and cough preparations contain
dextromethorphan.
This is not a sympathomimetic drug, but a cough suppressant. Dextromethorphan is on the list of forbidden medications because it can cause a hyperpyretic crisis. Dextromethorphan can be found in any drug with “DM” or “Tuss” in its name, as well as many preparations without these suffixes. A few examples are Bromarest-DM or -DX, Dimetane-DX Cough syrup, Dristan Cold & Flu, Phenergan with Dextromethorphan, Robitussin-DM, several Tylenol cold, cough, and flu preparations, and many other medications as well.

Because so many common over-the-counter medications contain sympathomimetics or dextromethorphan, it is nearly impossible to keep up with all of them. You can best protect yourself by reading the warning labels that come with these medications and by checking with your doctor or pharmacist before you combine any with an MAOI.

Diabetics taking MAOIs need to know that the MAOIs may also cause blood levels of insulin as well as some oral hypoglycemic agents to increase. As a result, your blood sugar may fall more than expected. This can cause a hypoglycemic reaction, with dizziness, faintness, sweating, and so forth, because your brain does not get enough sugar from your blood. Your doctor may have to adjust the doses of your diabetic medications if you are on an MAOI.

Any of the MAOIs can lower your blood pressure, and so they can intensify the effects of other blood-pressure medications your doctor has prescribed, including diuretics and beta-blockers. The MAOIs can also cause the blood levels of a number of blood-pressure medications to increase.
This also tends to intensify their effects. As noted above, some blood-pressure medications can have the paradoxical effect of causing an increase in blood pressure if you are taking an MAOI. Make sure you let your doctor know about the MAOI. Many major tranquilizers (neuroleptics) can also cause blood pressure to fall, and MAOIs can increase this effect as well.

Some painkillers must be avoided if you are taking an MAOI. For example, a single injection of the painkiller meperidine (Demerol) has been known to cause seizures, coma, and death in patients taking MAOIs. Other opiates, including morphine, are thought to be safer. Most mild nonprescription painkillers, such as aspirin or Tylenol, are also thought to be safe as long as they contain no caffeine. However, cyclobenzaprine (Fiexeril), which is commonly used to treat local muscle spasm, can cause fever, seizures, and death. This drug should be avoided entirely.

Many local and general anesthetics can also interact with the MAOIs. Some local anesthetics contain epinephrine or other sympathomimetic drugs that can create hypertensive reactions. Inform your dentist that you are taking an MAOI so she or he can choose a local anesthetic that will be safe for you. If you require elective surgery while on an MAOI, it would be best to discontinue the MAOI for one or two weeks prior to the surgery. Some general anesthetics, such as halothane, can cause excitement or excessive sedation as well as hyperpyretic reactions when combined with an MAOI. The muscle relaxants used by anesthesiologists, such as succinylcholine or tubocurarine, may also have more potent effects. Make sure you inform your anesthesiologist if you are taking an MAOI.

Sedative drugs, including alcohol, major tranquilizers (neuroleptics) and minor tranquilizers, barbiturates and sleeping pills, can interact with MAOIs. This is especially true for phenelzine (Nardil). Because phenelzine also tends to be sedating, it can enhance the effects of any other sedative agent. You should try to avoid combining MAOIs with sedative drugs because the sleepiness you experience
could be hazardous, especially if you are driving or operating dangerous machinery.

L-tryptophan is another sedative agent that should not be combined with MAOIs because it can cause a hyperpyretic crisis (serotonin syndrome). L-tryptophan is an essential amino acid that is present in certain foods such as meats and dairy products. It used to be available in health food stores and has been actively promoted as a natural sedative agent to help people with insomnia. It has also been used as a treatment for depression, but the evidence for its antidepressant effects is meager at best. Following ingestion, L-tryptophan rapidly accumulates in the brain, where it is converted into serotonin. If the dose of L-tryptophan is large enough, you will begin to feel sleepy. If you are taking an MAOI, the increase in brain serotonin may be massive. This is because your brain cannot metabolize the excess serotonin when you are on an MAOI, so the levels of serotonin can escalate to dangerous levels, triggering the serotonin syndrome.

However, some researchers have purposely treated depressed patients with an MAOI plus 2 to 6 grams per day of L-tryptophan in an attempt to make the MAOI treatment more effective. The purpose of these augmentation strategies is to convert a drug nonresponder into a drug responder. Some studies have indicated that this combination can be more potent than treatment with an MAOI alone. Such a treatment is somewhat dangerous, and should probably be administered by experts and reserved for patients with very difficult, resistant depressions.
²⁰
Dr. Jonathan Cole and his colleagues have given doses of 3 to 6 grams of L-tryptophan to patients who had been taking an MAOI for several weeks or more.
¹
They observed some early signs of the serotonin syndrome in these patients, suggesting the potential benefits of this drug combination may not be worth the risk.

In animal studies, the combination of lithium with an MAOI can also cause the serotonin syndrome. This is because lithium causes L-tryptophan to enter the brain more rapidly. L-tryptophan is present in the foods we eat, and a
large meal can contain as much as 1 gram of L-tryptophan. If you combine lithium with an MAOI, you may get a large increase in serotonin in your brain following meals. However, some doctors have added lithium to an MAOI if the MAOI has not been effective, in just the same way they might add L-tryptophan to try to augment the antidepressant effect of the MAOI. If you receive lithium plus an MAOI, you must be monitored closely to make sure you do not develop any symptoms of the serotonin syndrome, such as fever, tremor, jerking of the muscles, or confusion.

MAOIs are often combined with lithium for another reason. Bipolar patients with abnormal episodic mood elevations as well as depression are often maintained indefinitely on lithium or another mood stabilizer, as described below. During the depressed phase of the cycle, many bipolar patients will need an antidepressant as well as lithium to reverse the depression. The MAOIs, as well as many other kinds of antidepressants, have been used safely and successfully in this way. However, patients need to be monitored closely for signs of hyperpyretic crises as well as episodes of mania, which can occur on rare occasions when bipolar patients receive antidepressants.

Stimulants, pep pills, and weight-loss pills are especially dangerous when combined with MAOIs. Some of these drugs are categorized as sympathomimetics, and they can cause hypertensive crises. For example, methylphenidate (Ritalin), which is widely used for the treatment of attention deficit disorder in children and adults, is a sympathomimetic that could have this effect. Several commonly abused street or prescription drugs are also sympathomimetics. These include the amphetamines such as Benzedrine, Dexedrine, and Methedrine (also known as “speed” or “crank”) and cocaine. Amphetamines used to be prescribed for weight loss, but their abuse potential is so high that most doctors no longer prescribe them for this purpose. However, a number of the newer popular weight-loss drugs can also be quite dangerous when mixed with MAOIs. For example, phentermine (Adipex; Fastin) can cause hypertensive
reactions and fenfluramine (Pondimin), the controversial weight-loss drug that was recently in vogue, can lead to hyperpyretic crises.

As you know, caffeine is also a mild stimulant. It can cause racing of the heart, an irregular heartbeat, or increased blood pressure if you are taking an MAOI. Although coffee, tea, soda, and chocolate all contain caffeine, they are not strictly forbidden, especially in moderate amounts, because their effects are usually mild. Nevertheless, you should avoid caffeine in large quantities because it could precipitate a hypertensive crisis. Some experts recommend a daily maximum of two cups of coffee or tea, or two sodas. In addition, if you monitor your blood pressure with your own blood-pressure cuff, as described above, you can see whether that cup or two of coffee you love in the morning is actually causing a rise in blood pressure. If so, then you should cut down or give up caffeine completely while you are on the MAOI.

You can see in Table 20–9 that L-dopa (levodopa), which is used in the treatment of Parkinson’s disease, can also cause increases in blood pressure when combined with an MAOI. However, patients with Parkinson’s disease are sometimes treated with the MAOI selegiline, as well as other medicines. If these patients receive an MAOI along with L-dopa, the L-dopa should be started at a very small dose and increased slowly while checking the blood pressure.

As noted above, most of the forbidden drugs have warning labels to indicate they can be dangerous when combined with some antidepressant medications. If you are taking an MAOI, check the warning labels carefully before you take any new drug, and always check with your druggist or doctor as well. For a detailed list of drugs that cause hypertensive reactions for patients on MAOIs, see pages 157–160 of
Psychotropic Drugs Fast Facts
by Drs. Jerrold S. Max-men and Nicholas G. Ward.
¹⁷
The
Physician’s Desk Reference
(
PDR
)
²¹
also lists dangerous drug interactions for any prescription medication you may be taking. It is available in any library, drugstore, or medical clinic.

The lists of forbidden foods and medications may seem somewhat confusing or overwhelming. If your doctor prescribes an MAOI, she or he can give you a card to carry in your wallet that lists the foods and drugs to avoid. When in doubt, you can check the card. Some experts advise patients on MAOIs to carry Med-Alert cards so that any emergency room doctors will know that they are taking an MAOI in case they are in an accident or found unconscious and in need of emergency treatment. Then the doctors can take appropriate precautions when administering anesthesia or prescribing other drugs for you.

Remember that the chemical effects of an MAOI remain in your body for as much as one to two weeks after you stop taking it. This is why you must continue to observe the drug and dietary precautions for at least two weeks after you have taken your last MAOI. I would suggest that you actually wait a bit longer. Then you can begin to eat the forbidden foods, such as cheese, in small amounts at first, followed by blood-pressure checks. If your blood pressure is not affected, you can gradually increase the amount you eat until your diet is back to normal. Similarly, if you are switching from an MAOI to another antidepressant, you will have to be completely drug-free for two weeks after you take your last MAOI before starting the new antidepressant.

The same is true if you are starting an MAOI after you have taken another medication—you will have to wait for a period of time, depending on which medication you took. You will recall that you have to wait at least five weeks before starting an MAOI after going off Prozac because this drug remains in your blood for a prolonged time. Most of the other SSRIs are cleared out of your body more rapidly than Prozac, and so a two-week waiting period is usually sufficient. Some antidepressant drugs, such as nefazodone (Serzone) and trazodone (Desyrel), leave your body even faster, and you may have to wait only one week after taking them before starting an MAOI. Always check with your physician before making any changes in your medications.