molindone (Rx)

Frequency Not Defined

Drowsiness

Depression

Hyperactivity

Euphoria

Extrapyramidal symptoms

Akathisia

Parkinson syndrome

Dystonia

Tardive dyskineisa

Tachycardia

Nausea

Dry mouth

Salivation

Urinary retention

Constipation

Priapism

Amenorrhea

Gynecomastia

Galactorrhea

Libido increased

Leukopenia

Alteration in liver function tests

T-wave changes (transient, rare)

Lens opacities and pigmentary retinopathy

Rash

Contraindications

Documented hypersensitivity

Severe CNS depression (eg, alcohol, barbiturates, narcotics) or comatose states

Cautions

Tardive dyskinesia, a syndrome consisting of potentially irreversible, involuntary, dyskinetic movements, may develop in patients treated with antipsychotic drugs; if signs and symptoms of tardive dyskinesia appear in patients on antipsychotics, consider drug discontinuation; however, some patients may require treatment despite presence of the syndrome

May cause somnolence, postural hypotension, motor instability and sensory instability, which may lead to falls and, consequently, fractures or other injuries; complete fall-risk assessments for patients with diseases, conditions, or medications that could exacerbate these effects, when initiating antipsychotic treatment and recurrently for patients on long-term antipsychotic therapy

Neuroleptic malignant syndrome (NMS) reported with antipsychotic drug use; immediately discontinue therapy if it occurs along with nonessential concurrent therapy and administer intensive symptomatic treatment and monitor carefully; if patient requires antipsychotic drug treatment after recovery from NMS, it should be considered carefully and the patient monitored closely since recurrences of NMS have been reported

May cause drowsiness initially; advise patient against activities requiring mental alertness until response to the drug has been established

Convulsive seizures reported with use

Preparation contains calcium sulfate as an excipient; calcium ions may interfere with absorption of preparations containing phenytoin sodium and tetracyclines

Therapy may obscure signs of intestinal obstruction or brain tumor

Antipsychotic drugs elevate prolactin levels; elevation persists during long-term administration; although disturbances such as galactorrhea, amenorrhea, gynecomastia, and impotence have been reported, clinical significance of elevated serum prolactin levels is unknown for most patients

Therapy has not been shown effective in the management of behavioral complications in patients with mental retardation

In clinical trial and/or postmarketing experience, events of leukopenia/neutropenia and agranulocytosis have been reported temporally related to antipsychotic agents; possible risk factors for leukopenia/neutropenia include preexisting low white blood cell (WBC) count and history of drug-induced leukopenia/neutropenia; patients with clinically significant neutropenia should be carefully monitored for fever or other symptoms or signs of infection and treated promptly if such symptoms or signs occur; patients with severe neutropenia (absolute neutrophil count <1000/mm3) should discontinue therapy and have their WBC count followed until recovery

Pregnancy

Studies in pregnant patients have not been performed; animal reproductive studies have not demonstrated a teratogenic potential; anticipated benefits must be weighed against unknown risks to fetus if used in pregnant patients

Neonates exposed to antipsychotic drugs during third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery; agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding disorder reported in neonates; complications have varied in severity; while in some cases symptoms have been self-limited, in other cases neonates have required intensive care unit support and prolonged hospitalization

Lactation

Data not available on content of molindone hydrochloride in milk of nursing mothers

Mechanism of Action

Dihydroindolone derivative, which is not structurally related to phenothiazines, butyrophenones, or thioxanthenes; blocks postsynaptic dopaminergic receptors in the nucleus accumbens, striatum, and ventral tegmental area; has negligible affinity for the alpha-1 adrenergic receptor and the histamine H1 receptor in the frontal cortex; lacks affinity for the muscarinic acetylcholine receptor in the caudate nucleus and intermediate affinity for the alpha-2 adrenergic receptor in the frontal cortex

Absorption

Rapidly absorbed

Peak serum time: 1.5 hr

Duration: 24-36 hr

Distribution

Protein bound: 76%

Metabolism

Hepatic

Elimination

Half-life: 1.5 hr

Excretion: Urine and feces (2-3% unmetabolized)

Oral Administration

Initial and maintenance doses should be individualized

Storage

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F)

Keep tightly closed in light-resistant container