Is Hydralazine and Isosorbide Dinitrate (Bidil) affected by genetics?
Partially. 1 of 2 ingredients has pharmacogenetic evidence.
Hydralazine and isosorbide dinitrate contains 2 active ingredients, and 1 of them has published pharmacogenetic guidelines. The relevant gene is NAT2. Your genotype can change how that ingredient behaves in your body, while the other ingredients aren't affected by genetics in any clinically established way. The strongest evidence level on this page is Moderate, from the published guidelines shown below.
Also sold as Bidil.
Pharmacogenetic guidelines are written for one ingredient at a time, so the guidance below is for each ingredient on its own. What your genes mean for a combination product is less clear, because the dose and the other ingredients can change things. If you take Hydralazine and isosorbide dinitrate, it's worth talking over with your prescriber or pharmacist. How we handle combination products.
What's in Hydralazine and isosorbide dinitrate
Hydralazine Affected by NAT2
Affected by NAT2. Guidance from CPIC, moderate evidence.
Read the full hydralazine genetics guideIsosorbide dinitrate No known pharmacogenetics
No strong published pharmacogenetic guideline currently applies to isosorbide dinitrate.
Hydralazine phenotype recommendations
Published guidance from CPIC on how hydralazine should be dosed or substituted based on your NAT2 phenotype.
| Phenotype | What it means | Recommendation | Evidence |
|---|---|---|---|
| Rapid MetabolizerNAT2 | Your body breaks down hydralazine quickly. You will likely need a higher total daily dose to get a good effect. | CPIC Consider a starting total daily dose of at least 75 mg. Titrate up to 300 mg total daily hydralazine dose as tolerated. NAT2 rapid metabolizers typically require a 50-100% higher maintenance dose compared to poor metabolizers. |
Moderate |
| Intermediate MetabolizerNAT2 | Your body breaks down hydralazine somewhat quickly. You will likely need a higher total daily dose to get a good effect. | CPIC Consider a starting total daily dose of at least 75 mg. Titrate up to 300 mg total daily hydralazine dose as tolerated. NAT2 intermediate metabolizers typically require a 50-100% higher maintenance dose compared to poor metabolizers. |
Moderate |
| Poor MetabolizerNAT2 | Your body breaks down hydralazine slowly, which means you need a lower starting dose. Higher doses may increase side effects, including a rare immune reaction. | CPIC Initiate therapy at a total daily dose of 40 to 75 mg. Carefully titrate dose upward to clinical effect or guideline-recommended dose; use caution with total daily hydralazine doses of 200 mg or more. |
Moderate |
| IndeterminateNAT2 | Your NAT2 genotype does not give a clear result for hydralazine, so standard prescribing applies. | CPIC Use standard dosing. |
Not rated |
| Not availableNAT2 | We do not have a NAT2 result for you, so we cannot personalize guidance for hydralazine. | CPIC Use standard hydralazine dosing. |
Not rated |
Source: CPIC
The gene behind the guidance
NAT2 N-acetyltransferase 2
NAT2 helps metabolize hydralazine. Its inherited variants can produce slow, intermediate, or rapid acetylation, changing exposure at a given dose. CPIC provides hydralazine guidance based on the inferred acetylator phenotype.
In this report, poor metabolizer corresponds to slow acetylator. Dose selection still depends on blood pressure, tolerability, and the clinical indication.
See all drugs affected by NAT2Find out how your genetics affect Hydralazine and isosorbide dinitrate
Informational only, not medical advice. Pharmacogenetic guidance describes population-level patterns; your individual response depends on many factors. Never start, stop, or change a medication without talking to your prescribing clinician.