Drug information of Molindone


Drug group:

An indole derivative effective in schizophrenia and other psychoses and possibly useful in the treatment of the aggressive type of undersocialized conduct disorder.

Mechanism of effect

The exact mechanism has not been established, however, based on electroencephalogram (EEG) studies, molindone is thought to act by occupying (antagonizing) dopamine (D2) receptor sites in the reticular limbic systems in the brain, thus decreasing dopamine activity. Decreased dopamine activity results in decreased physiological effects normally induced by excessive dopamine stimulation, such as those typically seen in manifestations of psychotic disorders.


Molindone has a pharmacological profile in laboratory animals which predominantly resembles that of major tranquilizers causing reduction of spontaneous locomotion and aggressiveness, suppression of a conditioned response and antagonism of the bizarre stereotyped behavior and hyperactivity induced by amphetamines. In addition, molindone antagonizes the depression caused by the tranquilizing agent tetrabenazine.


Rapidly absorbed

Peak serum time: 1.5 hr

Duration: 24-36 hr

Protein bound: 76%

Metabolism: Hepatic

Half-life: 1.5 hr

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




Initial: 50-75 mg PO qDay; increase to 100 mg/day in 3-4 days; may titrate up or down based on severity of symptomatology and individual patient response


  • Mild: 5-15 mg PO q6-8hr
  • Moderate: 10-25 mg PO q6-8hr
  • Severe: 225 mg/day PO may be required

Dosage Modifications

  • Initiate at lower dose in elderly patients and debilitated patients

Dosing Considerations

  • When stopping antipsychotics, gradually taper dose over 6-24 months to avoid withdrawal


Safety and efficacy not established

Drug contraindications

Severe CNS depression


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

Black Box Warnings

Patients with dementia-related psychosis who are treated with antipsychotic drugs are at an increased risk for death, as shown in short-term controlled trials; deaths in trials appeared to be either cardiovascular (eg, heart failure, sudden death) or infectious (eg, pneumonia) in nature

Not approved for treatment of patients with dementia-related psychosis

Points of recommendation

  • Tell all of your health care providers that you take molindone. This includes your doctors, nurses, pharmacists, and dentists.
  • Avoid driving and doing other tasks or actions that call for you to be alert until you see how molindone affects you.
  • Do not stop taking molindone all of a sudden without calling your doctor. You may have a greater risk of side effects. If you need to stop molindone, you will want to slowly stop it as ordered by your doctor.
  • This medicine may prevent other drugs taken by mouth from getting into the body. If you take other drugs by mouth, you may need to take them at some other time than molindone. Talk with your doctor.
  • Low white blood cell counts have happened with drugs like this one. This may lead to a higher chance of getting an infection. Deadly infections have rarely happened. Tell your doctor if you have ever had a low white blood cell count. Call your doctor right away if you have signs of infection like fever, chills, or sore throat. Talk with your doctor.
  • Have blood work checked as you have been told by the doctor. Talk with the doctor.
  • Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
  • Dizziness, sleepiness, and feeling less stable may happen with molindone. These may lead to falling. Broken bones or other health problems can happen from falling. Talk with the doctor.
  • Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using molindone while you are pregnant.
  • Taking molindone in the third trimester of pregnancy may lead to muscle movements that cannot be controlled and withdrawal in the newborn. Talk with the doctor.
  • Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.
  • To gain the most benefit, do not miss doses.
  • Keep taking molindone as you have been told by your doctor or other health care provider, even if you feel well.
  • Take a missed dose as soon as you think about it.
  • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
  • Do not take 2 doses at the same time or extra doses.

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