Saphris

Asenapine is an atypical antipsychotic used to treat schizophrenia. Other atypical antipsychotic drugs include olanzapine (Zyprexa), quetiapine (Seroquel), ziprasidone (Geodon), iloperidone (Fanapt) and aripiprazole (Abilify).

Atypical antipsychotics differ from typical antipsychotics because they cause a lesser degree of movement (extrapyramidal) side effects and constipation.

The exact mechanism of action of asenapine is not known, but, like other anti-psychotics, it is believed that asenapine affects the way the brain works by interfering with communication among the brain's nerves. Nerves communicate with each other by making and releasing chemicals called neurotransmitters. The neurotransmitters travel to other nearby nerves where they attach to receptors on the nerves. The attachment of the neurotransmitters either stimulates or inhibits the function of the nearby nerves. Asenapine blocks several of the receptors on nerves including dopamine type 2, serotonin type 2, and alpha 2 adrenergic receptors.

It is believed that many psychotic illnesses are caused by abnormal communication among nerves in the brain, and that by altering communication through neurotransmitters, asenapine can alter the psychotic state. Asenapine was approved by the FDA in August, 2009.

The most common side effects of asenapine are

• drowsiness,
• headache, and
• dizziness.

Other side effects are

• fatigue,
•  insomnia,
• dry mouth,
• feeling restlessness or difficulty sitting still,
• stiffness and shuffling walk,
• tremors, and
• joint pain.

Less common but serious side effects include:

• Neuroleptic malignant syndrome (NMS). NMS is a rare but serious side effects associated with the use of antipsychotics. NMS may result in death and must be treated in the hospital. Signs and symptoms of NMS may include high fever, sweating (diaphoresis), severe muscle stiffness or rigidity, confusion, loss of consciousness, high blood pressure, rapid heartbeat, and changes in your breathing.
• Extrapyramidal side effects (EPS) including:
  • Dystonia: painful spasms of the oral, throat, or neck muscles that may cause problems with speech, swallowing, and stiff neck.
  • Akathisia: feelings of restlessness or difficulty sitting still.
  • Pseudoparkinsonis: drug induced Parkinson's symptoms.
• Tardive dyskinesia (TD). TD usually occurs after long term use of antipsychotics and usually presents with movement problems affecting the tongue, lips, jaw, face, and extremities.
• Metabolic changes including high blood sugar (hyperglycemia), diabetes mellitus, increase in blood cholesterol, and weight gain.
• High blood levels of prolactin. Prolactin is a hormone that allows the production of breast milk. High levels of prolactin may cause menstrual abnormalities, leakage of milk from the breast, development of breasts in men (gynecomastia), and erection problems in men (erectile dysfunction).

• The starting dose for treating schizophrenia in adults is 5 mg every 12 hours. The dose may be increased to 10 mg every 12 hours after 1 week.
• The dose for treating bipolar disorder is 5 to 10 mg every 12 hours.
• Asenapine sublingual tablets should be placed under the tongue and left to dissolve completely. Tablets dissolve within seconds and should not be swallowed. Ingestion of food and liquids should be avoided for 10 minutes after administration.

Asenapine can reduce blood pressure especially when standing up from a sitting down or laying down position (orthostatic hypotension). Therefore, asenapine should be used cautiously with other drugs also associated with orthostatic hypotension.

Asenapine may increase paroxetine (Paxil) blood levels by 2-fold. The dose of paroxetine should be reduced by half if it is used with asenapine.

Fluvoxamine (Luvox) may reduce breakdown of asenapine in the liver, increasing blood levels of asenapine. A smaller dose of asenapine should be considered.

Fetuses exposed to antipsychotics during the third trimester of pregnancy are at risk for extrapyramidal and withdrawal symptoms after birth. Symptoms reported included agitation, hypertonia, hypotonia, tremor, somnolence, depressed breathing, and feeding disorder. Currently there is no data on the use of asenapine during pregnancy. Asenapine should only be used during pregnancy if the potential benefit to the mother outweighs the potential for side effects in the unborn baby.

A pregnancy exposure registry has been established to monitor the use of atypical antipsychotics, including asenapine, during pregnancy. All pregnant women treated with atypical antipsychotics are advised to enroll in this pregnancy registry and report any side effects.

Asenapine has not been evaluated in breastfeeding women.

What preparations of asenapine are available?

Sublingual Tablets: 2.5, 5, and 10 mg

How should I keep asenapine stored?

Asenapine should be stored at room temperature, between 15 C to 30C (59 F and 86 F).