Phentermine and Tinnitus Risk
Tinnitus is not listed as a recognized side effect of phentermine (Adipex) in current obesity management guidelines, and there is no established causal relationship between phentermine use and tinnitus. 1
Documented Side Effects of Phentermine
The well-established adverse effects of phentermine include: 1
- Cardiovascular effects: Elevated blood pressure, elevated heart rate, palpitations, tachycardia, and ischemic events
- Central nervous system effects: Headache, insomnia, dizziness, restlessness, overstimulation, tremor, euphoria, dysphoria, anxiety, and rarely psychosis
- Gastrointestinal effects: Dry mouth, unpleasant taste, constipation, diarrhea
- Other effects: Impotence, changes in libido, urticaria
Evidence Regarding Drug-Induced Tinnitus
A comprehensive 2024 analysis of the FDA Adverse Event Reporting System (FAERS) database examined 29,460 patients with drug-related tinnitus from 2012-2023 and identified the top 25 tinnitus-associated drugs. 2 Phentermine was not among the drugs demonstrating significant association with tinnitus reports. 2 The drugs most strongly associated with tinnitus were duloxetine, ciprofloxacin, and adalimumab. 2
Clinical Context
While tinnitus can occur as a side effect of many medications, particularly those affecting biogenic amines in the central nervous system, 3 phentermine—despite being a sympathomimetic amine that affects norepinephrine—does not appear in the documented list of common tinnitus-inducing medications based on post-marketing surveillance data. 2
Practical Considerations
If a patient on phentermine develops tinnitus, investigate other potential causes including: 2
- Concomitant medications (particularly duloxetine, ciprofloxacin, or other known ototoxic drugs)
- Underlying conditions (depression, rheumatoid arthritis, multiple sclerosis)
- Pre-existing cochlear impairment 3
The extensive side effect profiles documented in multiple obesity management guidelines do not include tinnitus or other ototoxic effects. 1