Understanding Dovato and Its Importance
Dovato is a prescription medicine approved by the FDA for the treatment of Human Immunodeficiency Virus type 1 (HIV-1) infection in adults and adolescents meeting certain criteria [1.5.3]. It combines two antiretroviral drugs: dolutegravir, an integrase strand transfer inhibitor (INSTI), and lamivudine, a nucleoside analogue reverse transcriptase inhibitor (NRTI) [1.5.6]. This combination works by inhibiting the viral cycle at two different sites to suppress the virus [1.5.6]. As a complete regimen, Dovato should not be used with other HIV medicines [1.5.3]. For it to work effectively and safely, patients must be aware of potential interactions with other substances.
Absolute Contraindications: Do Not Take With Dovato
The most critical instruction is to never take Dovato if you are taking dofetilide (Tikosyn), a medication used for irregular heartbeat [1.2.2, 1.2.5]. Dolutegravir, a component of Dovato, can increase the plasma concentrations of dofetilide, leading to a risk of serious and potentially life-threatening events like long QT syndrome [1.2.1, 1.2.5]. Additionally, anyone with a history of a hypersensitivity reaction to either dolutegravir or lamivudine should not take Dovato [1.2.2, 1.2.3].
Prescription and Over-the-Counter (OTC) Drugs to Use with Caution
Several medications can interact with Dovato, either by reducing its effectiveness or by increasing the risk of side effects. It's essential to inform your healthcare provider of all medications you take [1.3.9].
Medications that can decrease Dovato's effectiveness:
- Anticonvulsants: Certain seizure medications like carbamazepine, oxcarbazepine, phenobarbital, and phenytoin can speed up the breakdown of Dovato, lowering its levels in the body and reducing its efficacy [1.2.5, 1.6.2]. For carbamazepine, a dose adjustment of dolutegravir may be required [1.2.3]. For others, coadministration should be avoided [1.2.3].
- Antimycobacterials: Rifampin, a drug used to treat tuberculosis, significantly decreases dolutegravir concentrations. An additional dose of dolutegravir is needed if taken with rifampin [1.2.3, 1.5.7].
- Polyvalent Cations: Antacids, laxatives, and other buffered medications containing polyvalent cations like magnesium, aluminum, calcium, or iron can bind to Dovato and prevent its proper absorption [1.2.1, 1.3.5]. To avoid this, you should take Dovato at least 2 hours before or 6 hours after taking these products [1.3.4, 1.3.9].
- Sorbitol: Chronic use of sorbitol, a sugar alcohol found in some liquid medications, can decrease the absorption of lamivudine, making Dovato less effective. It is best to avoid sorbitol-containing medicines when possible [1.2.1, 1.3.1].
Medications that can have their side effects increased by Dovato:
- Metformin: Dovato can increase the levels of metformin, a common diabetes medication, potentially increasing the risk of side effects like lactic acidosis [1.2.5]. Your doctor may need to adjust your metformin dosage [1.3.5].
- Dalfampridine: Taking dalfampridine with Dovato can lead to elevated levels of dalfampridine, which increases the risk of seizures [1.2.1, 1.3.4]. The benefits and risks should be carefully weighed by a doctor [1.3.4].
Herbal Supplements and Vitamins
Herbal products and supplements can also interfere with Dovato.
- St. John's Wort (Hypericum perforatum): This popular herbal supplement for depression should be avoided as it can significantly lower the levels of dolutegravir, making Dovato less effective and potentially leading to drug resistance [1.2.3, 1.3.1].
- Calcium and Iron Supplements: Similar to antacids, calcium and iron supplements (including multivitamins containing them) can interfere with Dovato's absorption [1.2.1, 1.3.1]. If you take Dovato on an empty stomach, you must separate the doses by taking Dovato 2 hours before or 6 hours after the supplement [1.3.4]. However, if you take Dovato with food, you can take these supplements at the same time [1.3.2, 1.4.4].
Comparison Table: Key Dovato Interactions
| Interacting Substance | Type of Substance | Potential Effect | Management Recommendation |
|---|---|---|---|
| Dofetilide (Tikosyn) | Prescription Drug | Increases dofetilide levels, risk of life-threatening events [1.2.5] | Contraindicated. Do not take together [1.2.2]. |
| St. John's Wort | Herbal Supplement | Decreases Dovato effectiveness, risk of resistance [1.3.1] | Avoid coadministration [1.2.3]. |
| Antacids/Laxatives (with Mg, Al, Ca) | OTC Medication | Decreases Dovato absorption and effectiveness [1.2.5] | Take Dovato 2 hours before or 6 hours after [1.3.4]. |
| Calcium or Iron Supplements | Supplement | Decreases Dovato absorption (on empty stomach) [1.3.4] | Separate doses (2h before/6h after) if fasting. Can take together with food [1.3.2]. |
| Carbamazepine, Rifampin | Prescription Drug | Decreases Dovato effectiveness [1.2.3] | Dose adjustment required (extra dolutegravir tablet) [1.5.7]. |
| Metformin | Prescription Drug | Increases metformin levels and risk of side effects [1.2.5] | Doctor may adjust metformin dose [1.3.5]. |
| Sorbitol | Additive/Laxative | Decreases Dovato effectiveness [1.3.1] | Avoid chronic use of sorbitol-containing medicines [1.3.4]. |
Pre-existing Health Conditions
Certain health conditions require special consideration before starting Dovato.
- Hepatitis B Virus (HBV): Dovato carries a boxed warning regarding HBV [1.2.5]. Stopping Dovato in patients co-infected with HIV-1 and HBV can lead to severe, acute exacerbations of hepatitis B [1.5.1]. All patients should be tested for HBV before starting Dovato [1.2.2].
- Kidney or Liver Impairment: Patients with severe kidney or liver problems may not be recommended to take Dovato, as it is a fixed-dose tablet that cannot be adjusted [1.2.3, 1.5.4]. People with underlying liver conditions like hepatitis C may be at an increased risk for liver-related side effects [1.2.9].
- Pregnancy: There is a potential risk of neural tube defects associated with dolutegravir when used at the time of conception and in early pregnancy. Effective contraception is advised [1.5.6].
Conclusion
To ensure the successful treatment of HIV-1 with Dovato, open communication with your healthcare provider is paramount. Always disclose all prescription drugs, over-the-counter medications, herbal supplements, and vitamins you are taking. Understanding and adhering to the guidelines on what to avoid when taking Dovato—from the absolute contraindication of dofetilide to the specific timing of supplements—is a critical step in maintaining your health and the medication's efficacy. Never stop or change your dose without consulting your doctor [1.2.6].
Authoritative Link: For detailed prescribing information, please refer to the FDA label for Dovato. [1.5.8]
