Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via Google Scholar Articles by Sirois, F. J. Search for Related Content PubMed Citation Articles by Sirois, F. J. Primary Care Syndromes Secondary to General Medical Disorders Other Somatic Therapy

Visual Hallucinations and Metoprolol

Metoprolol is widely used as a beta₁-adrenergic blocking agent in cardiology in the treatment of hypertension and arrythmias. It has the property of cardioselectivity without affecting the peripheral beta₂ receptors, notably the bronchi.¹

Beta-blocking agents are known, however, to have central nervous system (CNS) effects, some of which cause psychiatric syndromes.² It has been suggested that such side effects might be dependent upon some ancillary property like lipophilicity.^1,2 Lipophilic drugs are metabolized by the liver and thought to have the ability to enter the brain, as opposed to hydrophilic agents, like atenolol, which are excreted unchanged by the kidney.

Metoprolol is a lipophilic drug that can induce delirium, as reported earlier for the first agent in this category, propranolol,^3,4 which is less cardioselective than metoprolol, but more lipophilic.¹

However, reports of metoprolol-induced delirium are rare in the literature.⁵ We present here a case of delirium associated with metoprolol, with emphasis on the sequential building of symptoms, as opposed to a second case, where psychiatric symptoms were restricted to simple visual hallucinations. We suggest that in older patients with cognitive deficits, the primary presenting symptom of visual hallucinations may evolve into full-blown delirium.

Case Report 1

A 78-year-old woman, living with her husband, was seen in psychiatric consultation 6 days after her aortic valve-replacement surgery. On the night before, the consultant had been called because the patient was having visual hallicinations, was disoriented, wanted to leave and go home during the night, displayed sub-agitation, and appeared frightened.

Mini-Mental State Exam score before surgery was 24/30, and there were no previous psychiatric problems, but the patient had been found to be transiently disoriented 2 days earlier on the ward. Metoprolol had been started the day before consultation, at a dosage of 25 mg bid, with a first dose given at 10 A.M. and a second at 10 P.M. Other medication included only prn acetaminophen. Hypotension was not present.

Her daughter reported that when she had visited the evening before, her mother had told her she was seeing small insects on the wall in her room near another patient and had subsequently become afraid of that man. But the daughter had found her mother oriented and not confused and reported that her mother did not take any medication at bedtime. When seen, the patient reported that visual hallucinations had started early in the afternoon and that she later thought that the staff was "driving her crazy" with drugs. She felt panicky and insecure as night came on and wanted to leave immediately because her discharge was planned for the next day. She calmed down with a dose of 12.5 mg of methotrimeprazine. Discontinuation of metoprolol was advised in the morning; atenolol was started with no adverse effect, and the symptoms disappeared. The patient was discharged 24 hours later.

Case Report 2

A 57-year-old man was seen in psychiatric consultation 3 days after coronary-bypass surgery. He complained of visual hallucinations consisting of small insects creeping on the wall. Sensorium were clear, anxiety mild, without paranoid ideation, and no other psychiatric symptoms were noted. The patient was not excessively disturbed by the symptoms, but was annoyed and somehow bewildered. Metoprolol had been started during the day, at a dosage of 25 mg bid. As the patient was calmed, we explained to him that the symptoms were drug-induced and might abate with small doses of a neuroleptic. Reassurance and haloperidol 0.5 mg bid were enough for remission in 2–3 days.

Discussion

It has been shown that CNS or psychiatric side effects of beta-blockers are not dose-dependent.⁶ We want to focus the discussion upon the visual hallucinations as a primary symptom in those cases, which we have often seen in patients taking metoprolol. In patients without cognitive deficits, alert and otherwise well, hallucinations often remain an isolated symptom. With aged patients, often those with cognitive deficits or rather anxious or with fragile autonomy, visual hallucinations as primary symptoms will often produce fear and increasing disorganization, leading to a full-blown delirium. Such delirium remains, however, brief in time if metoprolol is discontinued rapidly. It is known that 70% of deliriums associated with metoprolol occur in people over age 70.⁵

Antipsychotic medication can be kept at minimal dosage. Age-related impairment in hepatic metabolism might be a contributing factor,⁷ but this was not investigated in those cases. It must be remembered that metoprolol has been found to have a brain/plasma concentration ratio about 20 times higher than atenolol,⁸ and that CNS side effects are probably the most frequent,⁹ and frequently start with isolated visual hallucinations without complete delirium in some cases.

Although the cases presented here suggest a rapid onset of psychiatric symptoms after metoprolol initiation, cases reported by Fisher et al.⁵ indicate that only about 58% display rapid symptom onset, within 1 week. All of Fisher et al.’s cases showed confusion and disorientation, which is not our experience with such patients, as we have stressed in the discussion. The relationship between lipophilicity and visual hallucinations is unclear. The appearance of visual hallucinations as a nuclear symptom in delirium associated with lipophilic beta-blockers remains to be confirmed.

REFERENCES

1. Cruickshank John: The clinical importance of cardio-selectivity and lipophilicity in beta-blockers. Am Heart J 1980; 100:160–178[CrossRef][Medline]
2. Conant J, Engler R, Janowsky D, et al: Central nervous system side effects of beta-adrenergic blocking agents with high and low lipid solubility. J Cardiovasc Pharmacol 1989; 13:656–661[Medline]
3. Fraser HS, Carr AC: Propranolol psychosis. Br J Psychiatry 1976; 129:508–509[Medline]
4. Shopsin B, Hirsch J, Gerolon S, et al: Visual hallucinations and propranolol. Biol Psychiatry 1975; 10:105–107[Medline]
5. Fisher AA, Davis M, Jeffery I: Acute delirium induced by metoprolol. Cardiovasc Drugs Ther 2002; 16:161–165[CrossRef][Medline]
6. Drayer DE: Lipophilicity, hydrophilicity, and the central nervous system side effects of beta-blockers. Pharmacotherapy 1987; 7:87–91[Medline]
7. Hickey PL, McLean AJ, Angus PW, et al: Increased sensitivity of propranolol clearance to reduced oxygen delivery in the isolated perfused cirrhotic rat liver. Gastroenterology 1996; 111:1039–1048[CrossRef][Medline]
8. Cruickshank JM, Neil-Dwyer G: Beta-blocker brain concentrations in man. Eur J Clin Pharmacol 1985; 28:21–23[CrossRef][Medline]
9. McAinsh J, Cruickshank JM: Beta-blockers and central nervous system side effects. Pharmacol Ther 1990; 46:163–197[CrossRef][Medline]

Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Email this article to a Colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to My Articles & Searches Download to citation manager Citing Articles via Google Scholar Articles by Sirois, F. J. Search for Related Content PubMed Citation Articles by Sirois, F. J. Primary Care Syndromes Secondary to General Medical Disorders Other Somatic Therapy

Get information about faster international access.

Privacy Policy

Copyright © 2006 Academy of Psychosomatic Medicine. All rights reserved.

Home | Search | Current Issue | Past Issues | Subscribe | All APPI Journals | Help | Contact Us