Two cases of sudden sensorineural hearing loss after methadone overdose.

OBJECTIVE

To document the presentation of 2 cases of sudden sensorineural hearing loss (SSHL) following methadone overdose.

CASE SUMMARY

We report 2 cases of acute, bilateral methadone-induced hearing loss that took place on the same night in our emergency department. A 30-year-old male and his 25-year-old wife were found unresponsive in their home after ingesting an unknown, but presumably large, quantity of methadone. Drugs that are typically categorized as ototoxic were ruled out in each patient via rapid in-house urine drug screens as well with a comprehensive analysis via gas chromatography mass spectrometry. Methadone and tetrahydrocannabinol (THC) were the only drugs found in the toxicology screenings that were common to both patients. The man had a long treatment course that included several days in the intensive care unit. The woman recovered completely and was discharged within a day of admission. The hearing loss in both patients reversed completely within 24 hours.

DISCUSSION

Several medications are commonly associated with ototoxicity, including nonsteroidal antiinflammatory drugs, antibiotics, loop diuretics, and chemotherapy agents. Although rare, drug-induced SSHL has been documented particularly among intravenous drug abusers after heroin injection. Until now, there has been only one published case report documenting drug-induced SSHL attributed to methadone.

CONCLUSIONS

We believe methadone to be the probable cause of SSHL in both patients, because it and THC were the only common drugs found on toxicology screens, a recent case report involved methadone-induced SSHL, and because of the suddenness of the onset and recovery of the patient's hearing coinciding with the time frame of the ingestion. The Naranjo probability scale score revealed that the adverse reaction was probable for each patient.