Kaplan + Sadock's Synopsis of Psychiatry, 11e

924

Chapter 29: Psychopharmacological Treatment

Table 29.2-1 Selected Medications Associated with Movement Disorders: Impact on Relevant Neuroreceptors Type (Subtype) Name (Brand) D 2 Blockade 5-HT 2

Blockade mACh Blockade

Antipsychotics Phenothiazine (Aliphatic) Phenothiazine (Piperidines)

Chlorpromazine (Thorazine) Thioridazine (Mellaril) Mesoridazine (Serentil) Trifluoperazine (Stelazine) Fluphenazine (Prolixin) Perphenazine (Trilafon) Chlorprothivene (Taractan) Loxapine (Loxitane) Haloperidol (Haldol) Droperidol (Inapsine) Molindone (Moban) Clozapine (Clozaril) Risperidone (Risperdal) Olanzapine (Zyprexa) Quetiapine (Seroquel) Ziprasidone (Geodon) Aripiprazole (Abilify) Pimozide (Orap) Thiothixene (Navane)

Low Low Low Med High High High Med Med High High High Med Low High Low

High Med Med Med Low Med Med High High Low Med Med Low High High High High High N/A Low

High High High Med Low Low Low Med Low Low Low Low High Low High Low Low Low N/A Low —

Phenothiazine (Piperazines)

Thioxanthenes

Dibenzoxazepines Butyrophenones

Diphenyl-butylpiperidines

Dihydroindolones Dibenzodiazepines

Benzisoxazole

Thienobenzodiazepines Dibenzothiazepines

Low/med

Low/med

Benzisothiazolvils

Med

Quinolones

High (as partial agonist)

Nonantipsychotic psychotropics Lithium (Eskalith)

N/A Low

Anticonvulsants Antidepressants Nonpsychotropics

Low (except amoxapine)

(Varies)

(Varies)

Prochlorperazine (Compazine)

High High

Med High

Low

Metoclopramide (Reglan)

—

D 2 , 5-hydroxytryptomine type 2; mACh, muscarinic acetylcholine; N/A, not applicable. (Adapted from Jantcak PG, David JM, Preshorn SH, et al. Principles and Practice of Psychopharmacotherapy. 3 rd ed. Philadelphia: Lippincott Williams & Wilkins; 2001, with permission.) , dopamine type 2; 5-HT 2

Neuroleptic-Induced Parkinsonism and Other Medication-Induced Parkinsonism Diagnosis, Signs, and Symptoms Symptoms of neuroleptic-induced parkinsonism and other med- ication-induced parkinsonism include muscle stiffness (lead pipe rigidity), cogwheel rigidity, shuffling gait, stooped posture, and drooling. The pill-rolling tremor of idiopathic parkinson- ism is rare, but a regular, coarse tremor similar to essential tremor may be present. The so-called rabbit syndrome, a tremor affecting the lips and perioral muscles, is another parkinsonian effect seen with antipsychotics, although perioral tremor is more likely than other tremors to occur late in the course of treatment. Epidemiology Parkinsonian adverse effects typically occur within 5 to 90 days of the initiation of treatment. Patients who are elderly and female are at the highest risk for neuroleptic-induced parkinson- ism, although the disorder can occur at all ages. Etiology Neuroleptic-induced parkinsonism is caused by the blockade of D 2 receptors in the caudate at the termination of the nigrostriatal

dopamine neurons. All antipsychotics can cause the symptoms, especially high-potency drugs with low levels of anticholinergic activity, most notably haloperidol (Haldol).

Differential Diagnosis Included in the differential diagnosis are idiopathic parkinson- ism, other organic causes of parkinsonism, and depression, which can also be associated with parkinsonian symptoms. Decreased psychomotor activity and blunted facial expression are symptoms of depression and idiopathic parkinsonism. Treatment Parkinsonism can be treated with anticholinergic agents, ben- ztropine (Cogentin), amantadine (Symmetrel), or diphenhydr- amine (Benadryl) (Table 29.2-2). Anticholinergics should be withdrawn after 4 to 6 weeks to assess whether tolerance to the parkinsonian effects has developed; about half of patients with neuroleptic-induced parkinsonism require continued treatment. Even after the antipsychotics are withdrawn, par- kinsonian symptoms can last up to 2 weeks and even up to 3 months in elderly patients. With such patients, the clinician may continue the anticholinergic drug after the antipsychotic has been stopped until the parkinsonian symptoms resolve completely.