1. Tricyclic Antidepressants

There are a number of possible side effects with tricyclic antidepressants that vary, depending on the medication. For example, amitriptyline (Elavil) may make people feel drowsy, while protriptyline (Vivactil) hardly does this at all and, in some people, may have an opposite effect, producing feelings of anxiety and restlessness. Because of this kind of variation in side effects, one antidepressant might be highly desirable for one person and not recommended for another. Tricyclics on occasion may complicate specific heart problems, and for this reason the physician should be aware of all such difficulties. Other side effects with tricyclics may include blurred vision, dry mouth, constipation, weight gain, dizziness when changing position, increased sweating, difficulty urinating, changes in sexual desire, decrease in sexual ability, muscle twitches, fatigue, and weakness. Not all these medications produce all side effects, and not everybody gets them. Some will disappear quickly, while others may remain for the length of treatment. Some side effects are similar to symptoms of depression (for instance, fatigue and constipation). For this reason, the patient or family should discuss all symptoms with the doctor, who may change the medication or dosage.

Tricyclics also may interact with thyroid hormone, antihypertensive medications, oral contraceptives, some blood coagulants, some sleeping medications, antipsychotic medications, diuretics, antihistamines, aspirin, bicarbonate of soda, vitamin C, alcohol, and tobacco.

An overdose of these antidepressants is serious and potentially lethal. It requires immediate medical attention. Symptoms of an overdose of tricyclic antidepressant medication develop within an hour and may start with rapid heartbeat, dilated pupils, flushed face, and agitation, and progress to confusion, loss of consciousness, seizures, irregular heart beats, cardiorespiratory collapse, and death.
2. The Newer SSRI Antidepressants

The most common side effects of these antidepressants are gastrointestinal problems and headaches. Some people complain of insomnia, anxiety, and agitation. Because of the potentially serious interaction between these medications and monoamine oxidase inhibitors, it is advisable to stop taking one medication from 2 to 4 or 5 weeks before starting the other, depending on the specific medications involved. In addition, some SSRIs have been found to affect metabolism of certain other medications in the liver, creating possible drug interactions. As with all medications, be sure to tell your physician if any other doctor, including your dentist, has prescribed any medications for you. This is necessary to prevent potentially dangerous drug interactions.
3. Monoamine Oxidase Inhibitors (MAOIs)

MAOIs may cause some side effects similar to those of the other antidepressants. Dizziness when changing position and rapid heartbeat are common. MAOIs also react with certain foods and alcoholic beverages (such as aged cheeses, foods containing monosodium glutamate (MSG), Chianti and other red wines), and other medications (such as over-the-counter cold and allergy preparations, local anesthetics, amphetamines, insulin, some narcotics, and antiparkinsonian medications). These reactions often do not appear for several hours. Signs may include severe high blood pressure, headache, nausea, vomiting, rapid heartbeat, possible confusion, psychotic symptoms, seizures, stroke, and coma. For this reason, people taking MAOIs must stay away from restricted foods, drinks, and medications. They should be sure that they are furnished, by their doctor or pharmacist, a list of all foods, beverages, and other medications that should be avoided.
Precautions to be Observed When Taking Antidepressants

When taking antidepressants, it is important to tell all your doctors (and dentists) about all medications being used, including over-the-counter preparations and alcohol. Antidepressants should be taken only in the amount prescribed and should be kept in a secure place away from children. When used with proper care, following the doctor’s instructions, antidepressants are useful medications that can control many of the physical symptoms of depression, while you work on changing the life stressors that contributed to its cause.