Understanding Antidepressant Medications (cont.)

Selective Serotonin Reuptake Inhibitors

Selective serotonin reuptake inhibitor (SSRI) medications affect the levels of serotonin in the brain. For many people, these medications are the first choice to treat depression. Examples of these medications are:

• fluoxetine (Prozac, Prozac Weekly, Sarafem),
  
  
• sertraline (Zoloft),
  
  
• paroxetine (Paxil, Paxil CR),
  
  
• escitalopram (Lexapro),
  
  
• fluvoxamine, and
  
  
• citalopram (Celexa).

How do SSRIs work?

The antidepressant action of SSRIs is not thoroughly understood but is possibly due to the ability of SSRIs to block the uptake of serotonin, thereby providing higher levels of serotonin at the brain receptor site.

Who should not use these medications?

• Individuals who are allergic to SSRIs



• Individuals who are currently taking, or have taken within the past two weeks, thioridazine (Mellaril), pimozide (Orap), or monoamine oxidase inhibitors (MAOIs) such as phenelzine (Nardil) and tranylcypromine (Parnate)



• Individuals must not take MAOIs or thioridazine for at least five weeks after stopping SSRIs.

Use

• SSRIs may be administered as oral tablets, capsules, or liquid once or twice a day. Prozac Weekly is administered once each week.



• Do not discontinue these medications abruptly, but gradually taper use to avoid withdrawal-like symptoms such as agitation, anxiety, confusion, dizziness, headache, and insomnia.



• Elderly individuals typically require lower doses of SSRIs.

Children: Fluoxetine (Prozac) is the only SSRI approved by the FDA for treatment of depression in children aged 8-18 years.

Drug or food interactions: Tell the doctor what medications are currently being taken because many medicines interact with SSRIs. Do not take any nonprescription or herbal medications without first consulting the doctor or pharmacist. The following are examples of interactions, but they do not represent a complete list.

• When an SSRI is administered with 5-HT1 agonists, such as sumatriptan (Imitrex) or zolmitriptan (Zomig), weakness and incoordination, although rare, have been reported.



• SSRIs may increase the blood levels and risk of toxicity of certain medications, including the following:
  
  
  • Highly protein-bound medicines such as warfarin (Coumadin) and digoxin
  (Lanoxin)
  
  
  • Antiarrhythmic medicines such as propafenone (Rythmol) or flecainide (Tambocor)
  
  
  
  • Beta blockers such as propranolol (Inderal) or metoprolol (Lopressor, Toprol XL)
  
  
  
  • Tricyclic antidepressants such as amitriptyline (Elavil)
  
  
  
  • Benzodiazepines such as alprazolam (Xanax), diazepam (Valium), midazolam (Versed), or triazolam (Halcion)
  
  
  
  • carbamazepine (Tegretol)
  
  
  
  • cisapride (Propulsid)
  
  
  
  • clozapine (Clozaril)
  
  
  
  • cyclosporine (Neoral, Sandimmune)
  
  
  
  • haloperidol (Haldol)
  
  
  
  • thioridazine (Mellaril)
  
  
  
  • phenytoin (Dilantin)
  
  
  
  • pimozide (Orap)
  
  
  
  • theophylline (Theo-Dur, TheoBid)
     
• The following substances may increase toxicity of SSRIs:
  
  
  • Alcohol or other drugs that depress the central nervous system
  
  
  
  • Diuretics (water pills)
  
  
  
  • MAOIs (may cause serious, and sometimes fatal, reactions)
  
  
  
  • St. John's wort
  
  
  
  • Decongestants such as pseudoephedrine (Sudafed)
  
  
  
  • lithium
  (Eskalith, Lithobid)
  
  
  • sibutramine (Meridia, Zolpmist)
  
  
  
  • zolpidem (Ambien) or other medications used for insomnia

Side Effects: This is NOT a complete list of side effects reported with SSRIs. A doctor, health care provider, or pharmacist can discuss a more complete list of side effects.

• Photosensitivity (increased risk of sunburn) (Use protective clothing, such as long sleeves and hats, and sunscreen to decrease the risk of sunburn.)



• Rash



• Nausea



• Dry mouth



• Constipation



• Low blood sodium levels (in people who are dehydrated or taking diuretics)



• Low blood sugar levels



• Drowsiness (Caution is advised when operating machinery, driving, or performing other tasks that require alertness.)



• Sexual dysfunction such as delayed ejaculation, erectile difficulties, and impotence (in men) and difficulty reaching climax or orgasm (in women)



• Withdrawal-like symptoms in newborns (Women who take SSRIs in late pregnancy [third trimester] may have newborns who require prolonged hospitalization due to withdrawal-like symptoms such as shortness of breath, constant crying, feeding difficulty, or low blood sugar levels.)



• Manic episodes in persons with bipolar disorder (If not combined with a mood-stabilizing medication, SSRIs may induce manic episodes in individuals with bipolar disorder [manic depression].)



• Kidney or liver impairment precautions (The doctor may draw blood samples to check for kidney or liver impairment before prescribing SSRIs.)

Next: Tricyclic Antidepressants »