Dovato (Dolutegravir/Lamivudine) Drug Interactions: What to Avoid and What to Tell Your Doctor

Dovato (dolutegravir/lamivudine) interacts with a number of medications, supplements, and herbal products. Some of these interactions are severe — potentially life-threatening. Others require timing adjustments or dose modifications.

Before starting Dovato, your doctor and pharmacist will review your full medication list. This guide gives you a plain-English overview of the most important interactions so you understand what to watch for and what to share with your care team.

Contraindicated Drug: Dofetilide (Tikosyn) — Do Not Use Together

This is the most critical interaction. Dofetilide (brand name Tikosyn) is an antiarrhythmic heart medication used to treat atrial fibrillation. Dolutegravir inhibits an enzyme (OCT2) that the kidneys use to clear dofetilide from the body. When taken together, dofetilide blood levels rise dangerously, causing potentially fatal heart arrhythmias.

If you currently take dofetilide, you cannot take Dovato. Period. This is a hard contraindication in the prescribing label. Your HIV provider and cardiologist will need to coordinate an alternative plan.

Drugs That Reduce Dovato's Effectiveness

Certain drugs speed up the breakdown of dolutegravir in the body (enzyme inducers), reducing its blood levels. If Dovato levels fall too low, HIV may not be adequately suppressed, risking viral rebound and resistance.

• Rifampin (Rifadin): A tuberculosis antibiotic. If rifampin cannot be avoided, the solution is to take Dovato once daily PLUS an additional standalone dolutegravir 50 mg tablet 12 hours later — total dolutegravir dose becomes 100 mg/day. This requires a separate dolutegravir prescription (Tivicay).
• Carbamazepine (Tegretol): An anticonvulsant/mood stabilizer. Same solution as rifampin — requires supplemental dolutegravir 50 mg taken 12 hours after Dovato.
• St. John's Wort: An herbal supplement used for depression. Significantly reduces dolutegravir levels — should be avoided entirely while on Dovato.

Antacids, Laxatives, and Supplements: Timing Matters

Dolutegravir can bind to polyvalent cations (metals like aluminum, magnesium, calcium, iron, zinc) in the gut, reducing its absorption. This affects a wide range of common products:

• Antacids/laxatives containing aluminum, magnesium, or calcium (e.g., Maalox, Milk of Magnesia, TUMS): Take Dovato at least 2 hours before OR 6 hours after these products.
• Buffered medications (e.g., buffered aspirin, some vitamin C formulations): Same 2-hour-before/6-hour-after rule.
• Iron and calcium supplements: If taken WITH food, you can take them at the same time as Dovato — food appears to reduce the interaction. Without food: 2-before/6-after rule applies.
• Multivitamins containing iron, calcium, or zinc: Same rules as above — take with food alongside Dovato, or space out.
• Sucralfate (Carafate): A stomach medication that binds cations — take Dovato 2 hours before or 6 hours after sucralfate.

Drugs That Dovato Can Affect

Dolutegravir inhibits certain drug transporters (OCT2 and MATE1), which affects how some drugs are cleared from the body:

• Metformin: Dolutegravir increases metformin blood levels. When starting, stopping, or dose-adjusting either drug, monitor for metformin toxicity (symptoms of lactic acidosis: nausea, vomiting, abdominal pain, weakness). Your doctor may adjust your metformin dose.
• Dofetilide (covered above as contraindicated): Also involves OCT2 inhibition — but the interaction is so severe it's a hard contraindication.

Sorbitol and Lamivudine Absorption

Sorbitol-containing liquid medications can reduce lamivudine absorption. This was primarily observed with lamivudine oral solution (not the Dovato tablet), but it's worth knowing if you're taking sorbitol-containing products. Stick to the tablet form of Dovato, which is not significantly affected.

What Doesn't Interact Significantly With Dovato?

Good news: dolutegravir does not interact significantly with oral contraceptives (birth control pills containing norgestimate and ethinyl estradiol), methadone, midazolam, rilpivirine, or daclatasvir. Many common medications can be safely used with Dovato — but always verify with your pharmacist or HIV provider before adding anything new.

Key Take-Home Rules

Quick reference for Dovato interactions:

• Never take with dofetilide. Contraindicated — can cause fatal arrhythmias.
• Avoid St. John's Wort entirely. Reduces dolutegravir to potentially sub-therapeutic levels.
• If taking rifampin or carbamazepine: Supplement with an additional dolutegravir 50 mg dose 12 hours after Dovato.
• Antacids and polyvalent cation products: Take 2 hours before or 6 hours after Dovato (or with food for supplements).
• Monitor metformin closely when starting or adjusting Dovato.

Tell your doctor and pharmacist about every medication, supplement, and herbal product you take before starting Dovato. For more on what to watch for while taking Dovato, see our guide on Dovato side effects.