Molindone is taken orally, and is rapidly absorbed and metabolized. Peak levels are reached within 90 minutes of taking the medication, and its effect lasts 24 to 36 hours. Molindone is available in 5-, 10-, 25-, and 100-mg tablets.

Recommended dosage

The dosage of molindone should be adjusted to the lowest level needed to control symptoms. The usual initial dosage is 50 to 75 mg per day. This may be increased to 100 mg per day three to four days after beginning treatment. A maximal dosage of up to 225 mg per day may be required.

Precautions

Prolonged or chronic administration of molindone increases the probability of developing tardive dyskinesia , a cluster of involuntary, uncoordinated movements that is potentially irreversible. These movements involve the head, neck, trunk, feet, and hands. Some of the movements involving the face and head include wormlike movement of the tongue, grimacing, chewing, and lip smacking. Tardive dyskinesia usually disappears once the affected person stops taking the medication, but it may not.

People who are comatose or are experiencing central nervous system depression from alcohol, barbiturates or narcotics are not prescribed this medication.

Drowsiness is often reported by people using molindone. For that reason, persons using molindone should not operate machinery or drive automobiles.

Molindone administration causes the level of pro-lactin (a hormone that initiates lactation) in the blood to rise. This is a potential problem for persons with a personal or family history of breast cancer. The drug may lead to the initiation of breast cancer. For this reason, the benefits of the drug must be carefully evaluated before it is administered.

Side effects

As stated, molindone has the potential to produce tardive dyskinesia. This is a syndrome consisting of involuntary, uncoordinated movements that is potentially irreversible. The incidence of tardive dyskinesia increases with increasing age and with increasing dosage of molindone. Tardive dyskinesia is more likely to occur after a long period of taking antipsychotic drugs, like molindone, but it may also appear after molindone use has been discontinued. Females are at greater risk than males for developing tardive dyskinesia. Involuntary movements of the tongue, jaw, mouth or face characterize tardive dyskinesia. These may be accompanied by involuntary movements of the arms, legs and trunk. There is no known effective treatment for tardive dyskinesia.

Parkinson-like symptoms have been linked with the administration of molindone. These include restlessness and agitation (akathisia) and difficulty walking or moving (dystonia). These are generally controlled with benztropine mesylate or trihexyphe-nidyl hydrochloride.

An occasionally reported side effect of molindone is neuroleptic malignant syndrome. This is a complicated and potentially fatal condition characterized by muscle rigidity, high fever, alterations in mental status, and cardiac symptoms such as irregular pulse or blood pressure, sweating, tachycardia and arrhythmias. This condition is considered a medical emergency.

Interactions

Molindone increases the effect of drugs and substances that depress the central nervous system. This class of drugs includes anesthetics, opiates, barbiturates, atropine and alcohol.

Molindone interferes with the absorption of phe-nytoin and tetracyclines.

See alsoSchizophrenia.

KEY TERMS

Akathisia —Agitated or restless movement, usually affecting the legs. Movement is accompanied by a sense of discomfort and an inability to sit, stand still, or remain inactive for periods of time. Akathisia is a common side effect of some neuroleptic (antipsychotic) medications.

Dystonia —A neurological disorder characterized by involuntary muscle spasms. The spasms can cause a painful twisting of the body and difficulty walking or moving.

Orthostatic hypotension —A sudden decrease in blood pressure due to a change in body position, as when moving from a sitting to standing position.

Schizophrenia —A severe mental illness in which a person has difficulty distinguishing what is real from what is not real. It is often characterized by hallucinations, delusions, language and communication disturbances, and withdrawal from people and social activities.

Tardive dyskinesia —A condition that involves involuntary movements of the tongue, jaw, mouth or face or other groups of skeletal muscles that usually occurs either late in antipsychotic therapy or even after the therapy is discontinued. It may be irreversible.

Tranquilizer —A medication that induces a feeling of calm and relaxation.

Resources

BOOKS

Adams, Michael and Norman Holland. Core Concepts in Pharmacology. Philadelphia: Lippincott-Raven, 1998.

Foreman, John C. and Torben Johansen. Textbook of Receptor Pharmacology. 2nd Ed. Boca Raton, FL: CRC Press, 2002.

Page, Clive P., and Michael Murphy. Integrated Pharmacology. St. Louis: Mosby-Year Book, 2002.

Von Boxtel, Chris J., Budiono Santoso, and I. Ralph Edwards. Drug Benefits and Risks: International Textbook of Clinical Pharmacology. New York: John Wiley and Sons, 2001.

PERIODICALS

Bagnall A., M. Fenton, R. Lewis, M. L. Leitner, and J. Kleijnen. “Molindone for schizophrenia and severe mental illness.” Cochrane Database Systematic Review no. 2 (2000), CD002083. Dhaware, B. S., J. J. Balsara, N. V. Nandal and A. G. Chandorkar. “Effects of amantadine on modification of dopamine-dependent behaviours by molindone.” Indian Journal of Medical Science 54, no. 8 (2000): 321-324.

W. M. Glazer. “Expected incidence of tardive dyskinesia associated with atypical antipsychotics.” Journal of Clinical Psychiatry. 61, Supplement 4 (2000): 21-26.

OTHER

American Academy of Clinical Toxicology. 777 East Park Drive, PO Box 8820, Harrisburg, PA 17105-8820. Telephone: (717) 558-7750. FAX: (717) 558-7845. Web site: http://www.clintox.org/index.html

American Medical Association, 515 N. State Street, Chicago, IL 60610. Telephone: (312) 464-5000. Web site: http://www.ama-assn.org/

American Academy of Family Physicians. 11400 Tomahawk Creek Parkway, Leawood, KS 66211-2672. Telephone: (913) 906-6000. Web site: http://www.aafp.org/

American Psychiatric Association. 1400 K Street NW, Washington, DC 20005. Telephone: (888) 357-7924. Fax: (202) 682-6850. Web site: http://www.psych.org/

American Society for Clinical Pharmacology and Therapeutics. 528 North Washington Street, Alexandria, VA 22314. Telephone: (703) 836-6981. Fax: (703) 836-5223.

American Society for Pharmacology and Experimental Therapeutics. 9650 Rockville Pike, Bethesda, MD 20814-3995. Telephone: (301) 530-7060. Fax: (301) 530-7061. Web site: http://www.aspet.org/

L. Fleming Fallon, Jr., M.D., Dr.P.H.

The Gale Encyclopedia of Mental Health