Kaplan + Sadock's Synopsis of Psychiatry, 11e

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Chapter 29: Psychopharmacological Treatment

Table 29.7-3 Dosage and Administration of Common Histamine Antagonists

Medication

Route

Preparation

Common Dosage

Diphenhydramine (Benadryl)

PO

Capsules and tablets: 25 mg, 50 mg

Adults: 25–50 mg three to four times per day Children: 5 mg/kg three to four times per day, not to exceed 300 mg/day

Liquid: 12.5 mg/5.0 mL

Deep IM or IV Solution: 10 or 50 mg/mL

Same as oral

Hydroxyzine

PO

Tablets: 10, 25, 50, and 100 mg

Adults: 50–100 mg three to four times daily

Hydrochloride (Atarax)

Syrup: 10 mg/5 mL

Children younger than 6 yrs of age: 2 mg/kg/day in divided doses Children older than 6 yrs of age: 12.5–25.0 mg three to four times daily

IM PO

Solution: 25 or 50 mg/mL Suspension: 25 mg/mL Capsules: 25, 50, and 100 mg Tablets: 15.2, 25.0, and 50.0 mg

Same as oral

Pamoate (Vistaril)

Same as dosages for hydrochloride

Promethazine (Phenergan)

PO

Adults: 50–100 mg three to four times daily for sedation Children: 12.5–25.0 mg at night for sedation

Syrup: 3.25 mg/5 mL

Rectal

Suppositories: 12.5, 25.0, and 50.0 mg

IM PO

Solution: 25 and 50 mg/mL

Cyproheptadine (Periactin)

Tablets: 4 mg

Adults: 4–20 mg/day

Syrup: 2 mg/5 mL

Children 2–7 yr of age: 2 mg two to three times daily (maximum, 12 mg/day) Children 7–14 yrs of age: 4 mg two to three times daily (maximum of 16 mg/day)

IM, intramuscular; IV, intravenous; PO, oral.

Doses of 100 mg have not been shown to be superior to doses of 50 mg, but they produce more anticholinergic effects than doses of 50 mg. Hydroxyzine is most commonly used as a short-term anxio- lytic. Hydroxyzine should not be given IV because it is irritating to the blood vessels. Dosages of 50 to 100 mg given orally four times a day for long-term treatment or 50 to 100 mg IM every 4 to 6 hours for short-term treatment are usually effective. SSRI-induced anorgasmia may sometimes be reversed with 4 to 16 mg a day of cyproheptadine taken by mouth 1 or 2 hours before anticipated sexual activity. A number of case reports and small studies have also reported that cyprohepta- dine may be of some use in the treatment of eating disorders, such as anorexia nervosa. Cyproheptadine is available in 4 mg tablets and a 2 mg/5 mL solution. Children and elderly patients are more sensitive to the effects of antihistamines than are young adults. R eferences Armstrong SC, Cozza KL. Antihistamines. Psychosomatics. 2003;44(5):430. Brown RE, Stevens DR, Haas HL. The physiology of brain histamine. Prog Neu- robiol. 2001;63(6):637. Camelo-Nunes IC. New antihistamines: A critical view. J Pediatr (Rio J). 2006; 82[5 Suppl]:S173. Davies AJ, Harindra V, McEwan A. Cardiotoxic effect with convulsions in terfena- dine overdose. BMJ. 1989;298(6669):325. Haas H, Panula P. The role of histamine and the tuberomammillary nucleus in the nervous system. Nat Rev Neurosci. 2003;4(2):121. Linnet K, Ejsing TB. A review on the impact of P-glycoprotein on the penetration of drugs into the brain. Focus on psychotropic drugs. Eur Neuropsychopharma- col. 2008;18(3):157. McIntyre RS. Antihistamines. In: Sadock BJ, Sadock VA, Ruiz P, eds. Kaplan & Sadock’s Comprehensive Textbook of Psychiatry. 9 th ed. Vol. 2. Philadelphia: Lippincott Williams & Wilkins; 2009:3033.

Montoro J, Sastre J, Bartra J, del Cuvillo A, Davila I. Effect of H 1 antihistamines upon the central nervous system. J Investig Allergol Clin Immunol. 2006; 16[Suppl 1]:24. Shapiro BJ, Lynch KL, Toochinda T, Lutnick A, Cheng HY, Kral AH. Prometha- zine misuse among methadone maintenance patients and community-based injection drug users. J Addict Med. 2013;7(2):96–101. Simons FE. Advances in H 1 -antihistamines. N Engl J Med. 2004;351(21):2203. Theunissen EL, Vermeeren A, Vuurman EF, Ramaekers JG. Stimulating effects of H 1 -antagonists. Curr Pharm Des. 2006;12(20):2501. Welch MJ, Meltzer EO, Simons FE. H 1 -antihistamines and the central nervous system. Clin Allergy Immunol. 2002;17:337. Yanai K, Tashiro M. The physiological and pathophysiological roles of neuronal histamine: An insight from human positron emission tomography studies. Phar- macol Ther. 2007;113(1):1.

▲▲ 29.8 Barbiturates and Similarly Acting Drugs

The first barbiturate to be used in medicine was barbital (Vero- nal), which was introduced in 1903. It was followed by phe- nobarbital (Luminal), amobarbital (Amytal), pentobarbital (Nembutal), secobarbital (Seconal), and thiopental (Pentothal). Many others have been synthesized, but only a handful has been used clinically (Table 29.8-1). Many problems are associated with these drugs, including high abuse and addiction potential, a narrow therapeutic range with low therapeutic index, and unfa- vorable side effects. The use of barbiturates and similar com- pounds such as meprobamate (Miltown) has practically been eliminated by the benzodiazepines and hypnotics, such as zol- pidem (Ambien), eszopiclone (Lunesta), and zaleplon (Sonata), which have a lower abuse potential and a higher therapeutic index than the barbiturates. Nevertheless, the barbiturates still