Benzonatate

Benzonatate (/bɛnˈzoʊnəteɪt/), sold under the brand name Tessalon among others, is a medication that is used for the symptomatic relief of cough. Benzonatate is taken by mouth. Effects generally begin within 20 minutes and last between 3 and 8 hours.

Side effects include sleepiness, dizziness, headache, upset stomach, skin rash, hallucinations, and allergic reactions. Overdosage can result in serious adverse effects including seizures, irregular heartbeat, cardiac arrest, and death. Overdose of only a small number of capsules can be fatal. Chewing or sucking on the capsule, releasing the drug into the mouth, can also lead to laryngospasm, bronchospasm, and circulatory collapse. It is unclear if use in pregnancy or breastfeeding is safe. Benzonatate is a local anesthetic and voltage-gated sodium channel blocker. It is theorized to work by inhibiting stretch receptors in the lungs, in turn suppressing the cough reflex in the brain. Benzonatate is structurally related to other local anesthetics like procaine and tetracaine.

Benzonatate was discovered in 1956 and was approved for medical use in the United States in 1958. It is available as a generic medication. Availability worldwide is limited, with the drug remaining marketed only in the United States and Mexico. In 2022, it was the 130th most commonly prescribed medication in the United States, with more than 4 million prescriptions. A 2023 systematic review found that there is inadequate evidence to support the effectiveness and safety of benzonatate for cough and highlighted rising safety concerns.