Is Hydrochlorothiazide and Metoprolol (Lopressor HCT) affected by genetics?
Partially. 1 of 2 ingredients has pharmacogenetic evidence.
Hydrochlorothiazide and metoprolol contains 2 active ingredients, and 1 of them has published pharmacogenetic guidelines. The relevant gene is CYP2D6. 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 Strong, from the published guidelines shown below.
Also sold as Lopressor HCT.
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 Hydrochlorothiazide and metoprolol, it's worth talking over with your prescriber or pharmacist. How we handle combination products.
What's in Hydrochlorothiazide and metoprolol
Hydrochlorothiazide No known pharmacogenetics
No strong published pharmacogenetic guideline currently applies to hydrochlorothiazide.
Metoprolol Affected by CYP2D6
Affected by CYP2D6. Guidance from CPIC, strong evidence.
Read the full metoprolol genetics guideMetoprolol phenotype recommendations
Published guidance from CPIC on how metoprolol should be dosed or substituted based on your CYP2D6 phenotype.
| Phenotype | What it means | Recommendation | Evidence |
|---|---|---|---|
| Ultrarapid MetabolizerCYP2D6 | Your body may clear metoprolol faster than usual, but there isn't enough evidence to know whether that changes how well it works, so there is no genetic recommendation. | CPIC No recommendation for metoprolol therapy due to insufficient evidence regarding diminished metoprolol effectiveness clinically. |
Not rated |
| Normal MetabolizerCYP2D6 | Your body processes the drug as expected; standard doses are likely to work well. | CPIC + CPIC + CPIC + CPIC Initiate standard dosing. |
Strong |
| Intermediate MetabolizerCYP2D6 | Your body processes the drug a bit more slowly, but no dose change is usually needed. | CPIC + CPIC + CPIC + CPIC Initiate standard dosing. |
Moderate |
| Poor MetabolizerCYP2D6 | Your body clears this drug very slowly, so it can build up. Your doctor may start with the lowest dose and watch your heart rate. | CPIC Initiate therapy with the lowest recommended starting dose. Carefully titrate dose upward to clinical effect or guideline-recommended dose; monitor more closely for bradycardia. Alternatively, consider selecting another beta-blocker. |
Moderate |
| IndeterminateCYP2D6 | The impact of your genotype on response to this drug is unknown. | CPIC Initiate therapy with recommended starting dose. |
Not rated |
| Not availableCYP2D6 | The impact of your genotype on response to this drug is unknown. | CPIC Initiate therapy with recommended starting dose. |
Not rated |
Source: CPIC
The gene behind the guidance
CYP2D6 Cytochrome P450 2D6
CYP2D6 is the most clinically important pharmacogene. It metabolizes around a quarter of all prescription drugs, including many antidepressants, opioids, and stimulants. The gene is unusually variable: roughly 7 percent of people are poor metabolizers (they barely activate CYP2D6), and another 1 to 3 percent are ultrarapid metabolizers (their enzyme is overactive).
The v4 report preserves the activity score used in its interpretation. Some medicines use a combined CYP2D6/CYP2C19 recommendation. CYP2D6 inhibitors can change functional metabolism; a genotype alone does not capture that effect.
See all drugs affected by CYP2D6Related medications
Find out how your genetics affect Hydrochlorothiazide and metoprolol
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.