Antidepressants work by affecting neurotransmitters that are used in the brain to communicate between neurons. Serotonin, dopamine and norepinephrine are some of the neurotransmitters that have a strong effect on mood. Antidepressants can be classified into different groups. These include, for example, monoamine oxidase inhibitors, selective serotonin reuptake inhibitors and tricyclic antidepressants. Some of the newest antidepressants don't seem to fit into any of these categories. All of these drugs have side effects, and it may take a while to find medication that diminishes or omits the depression symptoms while causing minimal side effects in a particular patient.
Suicide Risk
Many people who turn to antidepressant when feeling depressed or suicidal may find themselves feeling more suicidal after they start taking medication. This is often the case with children and young adults. The suicide risk should decrease over time, but patients need to be monitored carefully, especially during the first couple of months to see if their suicidal thoughts or actions increase. A person who is getting worse with the medicine may experience suddenly appearing symptoms such as anxiety, irritability, insomnia and aggression. Especially dangerous are suicidal thoughts and attempts.
Side Effects of Monoamine Oxidase Inhibitors
Some side effects, such as increased suicide risk, are typical for all antidepressants, but many of them have quite different side effects. MAOIs that elevate the levels of norepinephrine, serotonin and dopamine were the first antidepressants that were developed. They are still a choice for patients who suffer from major depression and who have not responded to other antidepressants. Yet, MAOIs have numerous problems. For example, MAOIs are associated with several significant drug interactions. MAOIs should not be taken together with drugs that that increase serotonin or norepinephrine activity, constrict blood vessels or inhibit monoamine oxidase. Combining MAOIs with drugs that increase serotonin may cause such symptoms as confusion, hyperactivity, coma or even death. If MAOIs are combined with norepinephrine or drugs that constrict blood vessels, blood pressure is likely to increase significantly. Patients should also avoid consuming any food that contains high levels of the monoamine tyramine. These include fish, chocolate, alcoholic beverages, different types of cheese, soy sauce and pickles. MAOIs combined with tyramine can cause high blood pressure, stroke or a hypertensive crisis. Some symptoms of this condition include headaches, heart palpitations, bleeding in the brain, chest pain, nausea, vomiting, neck stiffness or soreness and dilated pupils. Some typical side effects of MAOIs include headaches, insomnia, weight gain, hypertension and such sexual side effects as decreased sexual drive or erectile dysfunction.
Side Effects of Serotonin Reuptake Inhibitors
SSRIs are the most widely prescribed antidepressants that work by increasing the level of serotonin in the brain. They cause a range of side effects that include dry mouth, nausea, vomiting, diarrhea, sexual dysfunctions, nervousness, agitation, headaches, increased body temperature and insomnia. Also, patients who use SSRIs sometimes report changes in weight. In patients older than 65, SSRIs may increase the risk for falls and fractures. When combined with drugs that increase serotonin levels, the effects of SSRIs can be quite dangerous. Serotonin syndrome can follow, causing fever, confusion, high blood pressure, cardiac arrest, liver or kidney problems, coma and even death. MAOIs and St. John's wort should not be taken with SSRIs. The withdrawal symptoms of SSRIs can be quite serious if the medication is stopped abruptly.
Side Effects of Tricyclic Antidepressants
TCAs work by increasing norepinephrine and serotonin levels in the brain. Since TCAs may affect the heart's electrical conduction system, combining it with drugs that also have an effect on it may increase the frequency and severity of abnormal heart rate and rhythm. TCAs are not recommended for patients with cardiovascular conditions. Orthostatic hypotension, or temporary low blood pressure, has also been reported with the use of TCAs and can lead to dizziness, falls and fractures. Combining TCAs with clonidine may lead to high blood pressure. TCAs should not be combined with MAOIs. Side effects of TCAs may include sedation, constipation, dry mouth, sexual dysfunction, urinary hesitation and increased heart rate. Problems in vision and weight gain have also been reported. TCAs should not be used by patients with cognitive impairments, prostatic hypertrophy or narrow-angle glaucoma because there exists a risk that TCAs will increase symptoms caused by these conditions.
Antidepressant Withdrawal Symptoms
Stopping the use of antidepressant medication should never happen rapidly. Many antidepressants can cause severe withdrawal symptoms, such as anxiety, mood swings, irritability, crying spells, restlessness, dizziness, fatigue, stomach pain and flu-like symptoms. Such problems are especially common when a patient comes off such drugs as Paxil or Zoloft. Yet, all antidepressants can cause withdrawal symptoms. It is quite common for depression-like withdrawal symptoms to be more severe than the original depression itself. This may cause the patient to think that her depression has returned, and she may start taking the medication again. To avoid these problems, drug dosages should be decreased gradually, allowing for at least one to two weeks between each dosage reduction.
Member Comments