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Evaluation of Oral and Topical Minoxidil Exposures Reported to US Poison Centres from 1985–1991

A Report from the American Association of Poison Control Centers

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Summary

Minoxidil overdose occurs infrequently and little toxicity data are available. This study examines the epidemiology and clinical toxicity of minoxidil exposures to both tablets and topical solutions. All cases reported to the American Association of Poison Control Centers (AAPCC) Data Collection System from 1985 to 1991 were reviewed with respect to patient age, reason for and route of exposure, dosage form, co-ingestion, healthcare facility (HCF) referral/admission, treatment and medical outcome. 285 cases were reviewed. 145 (51%) occurred in children less than 6 years of age. 273 (96%) exposures were acute, 239 (84%) were accidental, 224 (79%) occurred via ingestion and 61 (21%) involved co-ingestion. 130 (46%) patients were referred to an HCF and 32 (11%) were admitted. The outcomes were: minor/no effect 59%, moderate 4.2%, major 1.8%, and 1 death. All topical exposures resulted in minor to no effects. Of 224 ingestions, 16 (7.1%) developed significant toxicity defined as moderate/major effects [AAPCC criteria] or death (one case involving tablets). In these 16 cases, 69% were intentional and 13 (81%) involved co-ingestion; the most frequent effects were hypotension (69%), tachycardia (38%) and lethargy (31%); 44% received intravenous fluids and vasopressors. Only 2 cases of hypotension were attributable to minoxidil alone (no history of co-ingested drugs); both responded to intravenous fluids and dopamine. The only death was a suicide, with co-ingestion of hydralazine, prazosin and paracetamol; terminal symptoms were intractable hypotension, coma and pulmonary oedema. It is concluded that significant toxicity after minoxidil exposure, regardless of formulation, is associated with oral administration, intentional exposure and co-ingestion of other agents.

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References

  1. Miller DD, Love DW. Evaluation of minoxidil. Am J Hosp Pharm 1980; 37: 808–14

    PubMed  CAS  Google Scholar 

  2. Linas SL, Nies AS. Minoxidil. Ann Int Med 1981; 94: 61–5

    PubMed  CAS  Google Scholar 

  3. Litovitz TL, Holm KC, Bailey KM, et al. 1991 Annual Report of the American Association of Poison Control Centers National Data Collection System. Am J Emerg Med 1992; 10(5): 452–505

    Article  PubMed  CAS  Google Scholar 

  4. Fleishaker JC, Andreadis NA, Welshman IR, et al. The pharmacokinetics of 2.5–10 mg oral doses of minoxidil in healthy volunteers. J Clin Pharmacol 1989; 29: 162–7

    PubMed  CAS  Google Scholar 

  5. Lowenthal DT, Affrime MG. Pharmacology and pharmacokinetics of minoxidil. J Cardiovasc Pharmacol 1980; 2 Suppl 2: S93

    Article  PubMed  Google Scholar 

  6. Poff SW, Rose SR. Minoxidil overdose with ECG changes: case report and review. J Emerg Med 1992; 10: 53–7

    Article  PubMed  CAS  Google Scholar 

  7. Allon M, Hall WD, Macon EJ. Prolonged hypotension after initial minoxidil dose. Arch Int Med 1986; 146: 2075–6

    Article  CAS  Google Scholar 

  8. Hall D, Charocopos F, Froer K-L, et al. ECG changes during long-term minoxidil therapy for severe hypertension. Arch Int Med 1979; 139: 790–4

    Article  CAS  Google Scholar 

  9. Krehlik JM, Hindson DA, Crowley JJ, et al. Minoxidil-associated pericarditis and fatal cardiac tamponade. West J Med 1985; 143: 527–9

    PubMed  CAS  Google Scholar 

  10. Pontremoli R, Robaudo C, Gaiter A, et al. Long-term minoxidil treatment in refractory hypertension and renal failure. Clin Nephral 1991; 35(1): 39–43

    CAS  Google Scholar 

  11. Tunkel AR, Shuman M, Popkin M, et al. Minoxidil-induced systemic lupus erythematosus. Arch Int Med 1987; 147: 599–600

    Article  CAS  Google Scholar 

  12. Mesfin GM, Piper RC, DuCharme DW, et al. Pathogenesis of cardiovascular alterations in dogs treated with minoxidil. Toxicologic Pathol 1989; 17(1): 164–81

    CAS  Google Scholar 

  13. Herman EH, Balazs T, Young R, et al. Acute cardiomyopathy induced by the vasodilating antihypertensive agent minoxidil. Toxicol Appl Pharmacol 1979; 47: 493–503

    Article  PubMed  CAS  Google Scholar 

  14. Herman EH, Ferrans VJ, Young RSK, et al. Examination of minoxidil-induced acute cardiotoxicity in miniature swine. Toxicology 1988; 48: 41–51

    Article  PubMed  CAS  Google Scholar 

  15. Herman EH, Ferrans VJ, Young RSK, et al. A comparative study of minoxidil-induced myocardial lesions in beagle dogs and miniature swine. Toxicologic Pathol 1989; 17(1): 182–92

    CAS  Google Scholar 

  16. Sobota JT. Review of cardiovascular findings in humans treated with minoxidil. Toxicologie Pathol 1989; 17(1): 193–202

    CAS  Google Scholar 

  17. Baker BA, Ruck B, Pellman E. Minoxidil-associated pericardial effusion. Drug Intell Clin Pharm 1987; 21: 753

    PubMed  CAS  Google Scholar 

  18. Connors TJ, Cooke DE, DeLauney WE, et al. Australian Trial of Topical Minoxidil and Placebo in Early Male Pattern Baldness. Australas J Dermatol 1990; 31: 17–25

    Article  PubMed  CAS  Google Scholar 

  19. Olsen EA, DeLong ER, Weiner MS. Long-term follow-up of men with male pattern baldness treated with topical minoxidil. J Am Acad Dermatol 1987; 16: 688–95

    Article  PubMed  CAS  Google Scholar 

  20. Rietschel RL, Duncan SH. Safety and efficacy of topical minoxidil in the management of androgenetic alopecia. J Am Acad Dermatol 1987; 16: 677–85

    Article  PubMed  CAS  Google Scholar 

  21. Ruas E, Goncalo M, Figueiredo A, et al. Allergic contact dermatitis from minoxidil. Contact Derm 1992; 26: 57–8

    Article  PubMed  CAS  Google Scholar 

  22. Spindler JR. The safety of topical minoxidil solution in the treatment of pattern baldness: the results of a 27-center trial. Clinics in Dermatol 1988; 6: 200–12

    Article  CAS  Google Scholar 

  23. Stern RS. Topical minoxidil. Arch Dermatol 1987; 123: 62–5

    Article  PubMed  CAS  Google Scholar 

  24. Wilson C, Walkden V, Powell S, et al. Contact dermatitis in reaction to 2% topical minoxidil solution. J Am Acad Dermatol 1991; 4: 661–2

    Article  Google Scholar 

  25. Colamarino R, Dubost JJ, Sauvezie B. Polymyalgia and minoxidil [letter]. Ann Int Med 1990; 113: 256–7

    PubMed  CAS  Google Scholar 

  26. Leenen FHH, Smith DL, Unger WP. Topical minoxidil: cardiac effects in bald men. Br J Clin Pharmacol 1988; 26: 481–5

    Article  PubMed  CAS  Google Scholar 

  27. Spindler JR. Deaths occurring during clinical studies of topical minoxidil. J Am Acad Dermatol 1987; 16: 725–9

    Article  PubMed  CAS  Google Scholar 

  28. Isles C, Mackay A, Barton PJM, et al. Accidental overdosage of minoxidil in a child [letter]. Lancet 1981; 1: 97

    Article  PubMed  CAS  Google Scholar 

  29. Royer ME, Ko H, Golbertson TJ. Radioimmunoassay of minoxidil in human serum. J Pharm Sci 1970; 66: 1266–9

    Article  Google Scholar 

  30. McCormick MA, Forman MH, Manoguerra AS. Severe toxicity from ingestion of a topical minoxidil preparation. Am J Emerg Med 1989; 7: 419–21

    Article  PubMed  CAS  Google Scholar 

  31. MacMillan AR, Warshawski FJ, Steinberg RA. Minoxidil overdose. Chest 1993; 103: 1290–1

    Article  PubMed  CAS  Google Scholar 

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Presented at the 1993 International Congress of Clinical Toxicology, September 10–13, 1993, New York, USA.

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Rose, S.R., Tomaszewski, C. Evaluation of Oral and Topical Minoxidil Exposures Reported to US Poison Centres from 1985–1991. Drug Invest 8, 81–94 (1994). https://doi.org/10.1007/BF03257431

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