Abstract
Methadone, a long-acting opiate agonist, and naltrexone, an opiate receptor antagonist, are both commonly used to treat patients with morphine and heroin addiction. We present a rare case of methadone-induced persistent bilateral sensorineural hearing loss (SNHL) after chronic naltrexone use and review opioid-induced hearing loss in the literature. Methadone-induced hearing loss has been described previously described in the literature with all reported cases recovering functional hearing. This is the first description of persistent bilateral severe SNHL following methadone ingestion. We propose opiate receptor sensitization from prolonged naltrexone use as a predisposing factor for methadone-induced irreversible cochlear injury.
1
Introduction
Opioids are the second most commonly abused illicit drug in the United States . Over the past decade, as the rate of opioid prescriptions has risen, the number of deaths from and admissions for substance abuse from prescription opioids has followed, demonstrating the profound medical and social impact of opioid abuse . Fortunately, there are several treatment options available. Methadone is a synthetic opioid with μ-receptor agonist and N -methyl- d -aspartic acid (NMDA) receptor antagonist activity, allowing its use in several therapeutic contexts including treatment for chronic pain and opioid dependence. Its μ-receptor agonist activity and high-fat solubility produces the same effects as heroin and morphine but with extended duration, thereby mitigating opioid withdrawal symptoms while simultaneously blocking their euphoric effects. In contrast, naltrexone is a competitive opioid receptor antagonist with greater receptor affinity than morphine or heroin. This property also allows it to be used in treating opioid dependence by directly preventing the binding and subsequent euphoric effects of opioids.
In 2010, approximately 12 million Americans reported abusing narcotic prescriptive medications and in 2009, nearly half a million emergency room visits were for treatment for opioid abuse and misuse . There are several well-known side effects from opioid overdose, however hearing loss is not generally recognized as a common one. Because of the prevalence of opioid abuse and treatment, understanding the risk of hearing loss in these patients is essential for both counseling and treatment. The exact mechanism of how this phenomenon occurs is unknown, but it is believed that cessation of the drug is the only treatment required . With reports of both reversible and permanent hearing loss, early recognition of this symptom may be the only way to prevent potentially reversible cochlear damage from progressing to becoming irreversible. The current literature on methadone-induced hearing loss has described a transient loss with almost complete hearing recovery once use of the drug was stopped. We present the first reported case of methadone-induced severe sensorineural hearing loss (SNHL) that failed to resolve in a patient after chronic naltrexone use and discuss possible mechanisms of injury to the inner ear. Understanding the mechanism of inner ear damage in opioid consumption has important implications in enhancing the current knowledge of inner ear homeostasis.
2
Case report
A 23-year-old male with a long history of struggling with multi-substance abuse was undergoing rehabilitation with naltrexone 50 mg per day for 3 months. He subsequently relapsed and began ingesting methadone 30 mg per day for 5 days. On the sixth day, he consumed 90 mg of methadone, resulting in respiratory arrest. The patient awoke with bilateral severe SNHL with word discrimination scores of 64% and 52% ( Fig. 1 ) in the right and left ears, respectively. Serial audiological evaluations over the next 9 months remained unchanged despite multiple high-dose steroid treatments. He denied vestibular symptoms and vestibular testing was normal. Given his profound sudden bilateral hearing loss, his quality of life was greatly diminished and he presented to our tertiary referral center for consideration for cochlear implantation.
2
Case report
A 23-year-old male with a long history of struggling with multi-substance abuse was undergoing rehabilitation with naltrexone 50 mg per day for 3 months. He subsequently relapsed and began ingesting methadone 30 mg per day for 5 days. On the sixth day, he consumed 90 mg of methadone, resulting in respiratory arrest. The patient awoke with bilateral severe SNHL with word discrimination scores of 64% and 52% ( Fig. 1 ) in the right and left ears, respectively. Serial audiological evaluations over the next 9 months remained unchanged despite multiple high-dose steroid treatments. He denied vestibular symptoms and vestibular testing was normal. Given his profound sudden bilateral hearing loss, his quality of life was greatly diminished and he presented to our tertiary referral center for consideration for cochlear implantation.
3
Discussion
Hearing loss after opioid consumption has only been rarely reported, but has a large impact on patients’ quality of life. Additionally, unraveling the pathophysiology behind opioid-induced hearing loss may advance the current understanding of inner ear homeostasis and possibly identify individuals at risk for developing SNHL. We reviewed 10 cases of hearing loss due to an opioid agent alone. Four cases were heroin induced, two were from propoxyphene use, and four cases were due to methadone use ( Table 1 ) .
| Author | Case | Opiate | Hearing loss | Vest sx | Treatment | Outcome |
|---|---|---|---|---|---|---|
| Ishiyama et al. | 47 M | Heroin | B sudden profound downsloping SNHL | + | Resolved | |
| Kortequee et al. | 26 M | Heroin | U sudden profound flat SNHL | + | Persistent | |
| Schrock et al. | 23 M | Heroin | B sudden profound flat SNHL | − | Prednisolone | Partially recovered |
| Pentoxyphylline | ||||||
| Nair et al. | 29 F | Heroin | B sudden profound mid frequency SNHL | − | Steroids | Partially recovered |
| Naloxone | ||||||
| Van Gaalen et al. | 37 M | Methadone | B sudden profound flat SNHL | − | Resolved | |
| Christenson and Marjala | 30 M | Methadone | B sudden hearing loss | − | Resolved | |
| 25 F | Methadone | B sudden hearing loss | − | Resolved | ||
| Shaw et al. | 20 M | Methadone | B sudden hearing loss | − | Resolved | |
| Lupin and Harley | 22 M | Propoxyphene | B sudden severe downsloping SNHL | + | Persistent | |
| Harell et al. | 30 M | Propoxyphene | B gradual severe downsloping SNHL | + | Progressed to deafness |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
