Acamprosate vs naltrexone: the 30-second answer
Both are first-line, FDA-approved medications for alcohol use disorder — but they solve different problems. Naltrexone targets the front end of drinking: it blunts craving and the rewarding buzz, cutting heavy-drinking days, and works even if you have not fully stopped. Acamprosate (Campral) targets the aftermath: started once you are abstinent, it calms the lingering brain over-excitation of early sobriety — the restlessness, insomnia, and unease that drive relapse — and helps you stay stopped. Reduce drinking: naltrexone. Protect abstinence: acamprosate.
How they work in the brain
Naltrexone blocks mu-opioid receptors, interrupting the endorphin reward that alcohol triggers — drinking becomes flat rather than pleasurable. Acamprosate works on the glutamate/GABA axis: chronic alcohol leaves the glutamate system stuck in overdrive after quitting, and acamprosate helps rebalance that excitatory tone, easing protracted withdrawal symptoms over the months when relapse risk peaks. Mechanistic details at MedlinePlus (naltrexone) and MedlinePlus (acamprosate).
Dosing and daily reality
The practical gap is pill burden. Naltrexone: one 50 mg tablet daily, or the monthly Vivitrol injection that removes daily adherence entirely. Acamprosate: two 333 mg tablets three times a day — six pills daily — which is the medication’s honest weakness; pillboxes and phone alarms are part of the prescription. Campral is simply the brand name for acamprosate; generic acamprosate calcium is the same drug.
Liver vs kidneys: the decisive safety split
This is the cleanest tiebreaker. Naltrexone is metabolized hepatically and avoided in acute hepatitis or liver failure — a real constraint since alcohol-related liver disease is common. Acamprosate is not metabolized by the liver at all: it clears through the kidneys unchanged, making it the standard choice with liver disease (and conversely, it is dose-adjusted or avoided in significant renal impairment). Alcoholic hepatitis pushes toward acamprosate; kidney disease pushes toward naltrexone.
Which is more effective?
Meta-analyses put them in the same league with different strengths: naltrexone shows the stronger signal for reducing heavy drinking and craving; acamprosate shows the stronger signal for maintaining continuous abstinence once stopped, with effects that build over months. The landmark COMBINE trial found naltrexone plus medical management effective, while acamprosate results shine more in European abstinence-oriented trials — a pattern consistent with the goal split above, summarized in the NIAAA clinician resource.
Can you take acamprosate and naltrexone together?
Yes — the combination is used clinically and was studied directly in COMBINE: mechanisms are complementary (reward blockade plus glutamate rebalancing), there is no direct interaction, and organ routes differ (liver vs kidneys). Evidence that the combination beats well-dosed monotherapy is mixed, so the typical path is optimizing one first, adding the second when craving and post-acute symptoms both persist. Prescriber judgment rules here.
Acamprosate alternatives and the bigger toolkit
If acamprosate is not a fit, alternatives include naltrexone itself, disulfiram (Antabuse) as a deterrent for supervised, high-motivation settings, and off-label options prescribers sometimes reach for (topiramate, gabapentin) in specific profiles. Whatever the medication, guidelines pair it with counseling — and if drinking is currently heavy and daily, supervised detox comes first because alcohol withdrawal can be dangerous. Our helpline (833) 567-5838 finds MAT-friendly programs by state and insurance.
Sources
MedlinePlus: Acamprosate · MedlinePlus: Naltrexone · NIAAA: Medications for AUD · SAMHSA: Medications for SUD · NIDA: Principles of Effective Treatment