What Are Selective Serotonin Reuptake Inhibitors (SSRIs)?

As you can see, not every SSRI is FDA-approved to treat every mood-related disorder.

Off-Label Uses for SSRIs

Doctors may prescribe SSRIs off-label to treat a broad range of other conditions. Among them are eating disorders, fibromyalgia, migraine headaches, and premature ejaculation.

"Off-label" refers to when a physician prescribes a medication for a purpose other than what it has been approved to treat. For example, Paxil and Zoloft are the only SSRIs approved by the FDA for PTSD, but some healthcare providers may prescribe Prozac off-label.

Prescribing a drug off-label can mean prescribing it for:

• A different age range: Treating children with a medication that has been approved for use in adults only
• A different condition: When a medication is used for a condition that it is not approved to treat
• At a different dosage: When a medication is dosed differently than what has been approved

Precautions and Contraindications With SSRIs

SSRIs are not for everyone and must be used with caution in certain individuals. It is important to speak to your care provider about any preexisting conditions you may have before starting an SSRI.

Pregnancy

Hundreds of studies have looked at SSRI exposure and birth defects. With the exception of Paxil, most SSRIs are generally considered safe to use during pregnancy. But they are not without risk.

Although rare, the following are risks that have been linked to SSRI use during pregnancy:

• Birth defects: SSRI use during pregnancy may increase the risk of abdominal, heart, and lung birth defects.
• Blood loss after childbirth: Some studies have reported a slightly higher risk of postpartum hemorrhage among women on SSRIs.
• Miscarriage or premature birth: A person who is pregnant and taking antidepressants is at increased risk for a number of complications, including miscarriage and premature delivery.
• Psychiatric disorders in children: Children of pregnant people who used antidepressants before and during pregnancy have a higher risk of developing a psychiatric disorder. However, this association may be attributable to the severity of the parent’s underlying condition.
• Withdrawal symptoms in newborns: Newborns exposed to SSRIs in the last trimester may experience withdrawal symptoms such as hypoglycemia, tremors, tachycardia, rapid breathing, and respiratory distress.

Letting depression go untreated can also have a negative impact on a pregnancy. Remember to always discuss your specific situation thoroughly with your care provider before discontinuing any medication.

Breastfeeding

It's possible that SSRIs can be passed to your baby through your breastmilk. If you're pregnant (or trying to become pregnant) and wish to breastfeed, try to choose an antidepressant that is safe to use both during pregnancy and breastfeeding. 

Zoloft and Paxil have been widely studied and are considered relatively safe for use during breastfeeding. The data suggest that the amount of these drugs nursing infants are exposed to is low enough that there are no adverse effects.

Children

In 2004, the FDA issued a black box warning—the agency's strictest warning—that young people (up to age 25) taking antidepressants might experience increased suicidal thoughts and behaviors.

The warning also says that children and adolescents taking SSRIs should be carefully watched for sudden changes in their mood or actions, such as:

• Aggressive or hostile behavior
• Extreme increase in movement and talking
• Making suicidal statements
• Trouble sleeping
• Withdrawal from friends and family

If you see any of these signs in your child, particularly if they are new or noticeably worse than before, talk to a healthcare provider as soon as possible.

Side Effects of SSRI Medications

SSRIs are considered the most effective antidepressants with the fewest side effects. The majority of people who take them, however, do experience at least one side effect. Most of them are minor and usually go away as your body gets used to the medication.

Common side effects of SSRIs include:

• Diarrhea
• Drowsiness
• Dry mouth
• Headache
• Increased sweating
• Insomnia
• Nausea and vomiting
• Sexual dysfunction (delayed or absent orgasm and decreased libido)
• Weight gain
• Anxiety

Consult with a physician so they can explain all the known side effects of your chosen SSRI. If you're experiencing one or more of these side effects, let them know. They may be able to suggest ways to lessen the effects or adjust your dose as needed.

Serotonin Syndrome

SSRIs aren't the only medications that increase serotonin levels in your body. Certain pain and migraine medications, and herbal supplements such as St. John's wort, can also increase serotonin levels. Taking two or more of these drugs (also known as serotonergic drugs) can lead to a condition called serotonin syndrome.

If too much serotonin builds up in your body, you may experience:

• Autonomic effects: Abnormally fast heart rate, hypertension, hyperthermia, shivering, sweating
• Mental status effects: Confusion, delirium, excitement, restlessness, and hallucinations
• Neuromuscular effects: Muscle twitching, tremors, and increased reflexes

Though rare, serotonin syndrome may be life-threatening if not treated immediately.

Discontinuation Syndrome

SSRIs work by altering neurotransmitter levels. Neurotransmitters are the chemical messengers that attach to neurons throughout the body and influence their activity.

Neurons eventually adapt to the new level of neurotransmitters. But if the level changes too much too quickly—for example, because you've suddenly stopped taking your antidepressant—it can lead to uncomfortable withdrawal symptoms such as:

• Feeling anxious
• Flu-like symptoms
• Hyperarousal
• Nausea
• Sensory disturbances
• Trouble sleeping

Symptoms occur within two to four days after drug cessation and usually last one to two weeks.

Paroxetine is linked with the highest incidence of discontinuation syndrome, whereas fluoxetine is linked with the lowest. In general, lower doses of SSRIs are associated with fewer occurrences of discontinuation syndrome.

Treatment for discontinuation syndrome depends on your individual symptoms, which SSRI you were taking, and your dosage. Recommendations for potentially lessening symptoms include tapering gradually off your dosage instead of stopping immediately, as well as switching from your current SSRI to the more slowly metabolized fluoxetine.

Discontinuation syndrome is not life-threatening and symptoms should subside within a few weeks. Talk to your physician before discontinuing your medication; they can help you develop a strategy to hopefully minimize any symptoms.