Gabapentin

Is gabapentin safe?

For most people, yes, with caveats. Gabapentin rarely causes serious harm on its own at labelled doses, and an overdose of gabapentin alone is seldom fatal. The common problem is that it makes people drowsy and unsteady. The serious problem is what happens when it is taken with opioids, other sedatives or alcohol, or by someone with weak lungs: breathing can slow to a life-threatening degree. We score it 66, below sertraline and well above oxycodone.

It is one of the most prescribed medicines in the US, about 69 million prescriptions in 2019 according to the CDC, and much of that use is off-label for back pain, migraine, anxiety and sleep.

The 2019 FDA breathing warning

On 19 December 2019 the FDA warned that gabapentin and pregabalin can cause serious breathing difficulties in people with respiratory risk factors. The agency named four:

• taking an opioid
• taking another drug that depresses the brain, such as benzodiazepines, sedating antihistamines or some antidepressants
• lung disease such as COPD
• older age

It required new warnings on every gabapentinoid label and asked manufacturers to run trials of their misuse potential, especially with opioids. The current Neurontin label says case reports, human studies and animal studies link gabapentin with serious, life-threatening or fatal breathing depression in these settings, and advises starting at a low dose.

Watch for confusion, unusual dizziness, extreme sleepiness, slow or shallow breathing, unresponsiveness, or bluish lips, fingers or toes. These need emergency care.

Gabapentin in overdose deaths

A CDC analysis of 58,362 US overdose deaths with toxicology results in 2019 and 2020 found gabapentin in 5,687 (9.7%). In just over half of those it was judged to have contributed to death, and an opioid was involved in 85% to 90%, increasingly illicit fentanyl. The CDC described gabapentin as generally safe and rarely linked to overdose on its own; the danger is the combination. In England and Wales, gabapentin was mentioned on 160 drug poisoning death certificates registered in 2024, up from 26 in 2014, but in only 10 was no other drug involved (ONS). Pregabalin was mentioned on 617.

Misuse, dependence and the UK reclassification

Gabapentin does not act on opioid or benzodiazepine receptors, and its label does not list it as a controlled substanceControlled substanceA medicine or drug that the law restricts because it can be misused or cause dependence. Countries group them into schedules or classes.More in the glossary. But misuse is reported, often at high doses and mostly by people with a history of misusing several drugs. The label asks prescribers to check for a history of drug misuse and to watch for dose escalation and drug-seeking.

In the UK, from 1 April 2019 gabapentin and pregabalin became Class C drugs under the Misuse of Drugs Act and Schedule 3 under the 2001 regulations. Prescriptions now have special writing requirements and are valid for 28 days. In the US, Kentucky listed gabapentin as Schedule V in 2017, and several other states followed.

In January 2026 the MHRA said UK leaflets and packs for gabapentinoids, benzodiazepines and Z-drugs would carry stronger warnings on addiction, dependence and withdrawal, and that prescribers should agree a plan for stopping before treatment starts.

Stopping suddenly after regular use can cause withdrawal within about 48 hours: anxiety, insomnia, sweating, nausea, pain, confusion and, in people with epilepsy, seizures. The label advises tapering over at least a week.

Doses on the label

Use	Neurontin label (US)
Nerve pain after shingles	300 mg on day 1, 600 mg on day 2, 900 mg on day 3, then up to 1,800 mg a day in three doses
Partial-onset seizures, 12 and over	Start 300 mg three times a day; usual 300 to 600 mg three times a day
Reduced kidney function	Lower doses, set by creatinine clearance

In the nerve pain trials, doses above 1,800 mg a day did not add benefit, although up to 3,600 mg was studied. The NHS lists 900 mg to 3,600 mg a day for both nerve pain and epilepsy. Gaps between doses should not exceed 12 hours.

Other side effects to know

Drowsiness affected 21% and dizziness 28% of people in the nerve pain trials, against 5% and 8% on placebo. Driving studies with a related drug showed significant impairment, and the label warns that people often cannot judge how impaired they are. Rare but serious reactions include DRESS, a multi-organ allergic reaction that has been fatal, and anaphylaxis with swelling of the lips and throat. Like all antiepileptics it carries a small increase in suicidal thoughts. Children aged 3 to 12 may become hostile or hyperactive.

Who should be careful

Talk to your doctor or pharmacist before taking gabapentin if you:

• take an opioid, a benzodiazepine such as alprazolam, sleeping pills, or drink regularly
• have COPD, severe asthma or sleep apnoea
• have kidney disease or are over 65
• have ever misused drugs or alcohol
• are pregnant or planning a pregnancy

Take antacids at least two hours apart from gabapentin, because they cut absorption by about 20%. Do not drive until you know how it affects you.

How we scored it

Track record (92) is the strongest factor after three decades of very wide use. Serious side effects (70) and overdose marginOverdose marginHow far a normal dose is from a harmful one. A wide margin means an accidental extra dose is unlikely to cause serious harm.More in the glossary (65) are moderate because harm on its own is uncommon. Interactions (55), dependence (60) and regulatory warnings (60) are held back by the opioid combination risk, the 2019 FDA warning and the UK reclassification.