Dutasteride and Rosuvastatin Interaction: Safety, Metabolism, and Monitoring

Updated May 25, 2026

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Dutasteride (brand name Avodart, a 5-alpha reductase inhibitor used for benign prostatic hyperplasia) and rosuvastatin (brand name Crestor, a statin used to lower LDL cholesterol) do not share a metabolic pathway. Dutasteride is cleared mainly by the liver enzyme CYP3A4; rosuvastatin undergoes very little enzymatic metabolism and is eliminated largely unchanged, with its plasma levels governed instead by liver-uptake transporters (OATP1B1, OATP1B3) and the efflux transporter BCRP. Neither the Avodart nor the Crestor FDA label lists the other drug as an interacting agent, and no pharmacokinetic mechanism in either label predicts a clinically significant interaction between them. That absence of a shared pathway, not an absence of scrutiny, is why the combination is generally considered low risk, though "no known interaction" is a statement about mechanism and labeling, not a guarantee drawn from a dedicated interaction trial in this exact pair.

Why this combination comes up so often

Age is the connecting variable. Benign prostatic hyperplasia becomes more common through a man's 50s and 60s, and the same decades are when statin therapy is commonly started for cardiovascular risk reduction under current lipid guidelines. Because both conditions track with age, it is common for the same patient to be prescribed a 5-alpha reductase inhibitor and a statin at the same time, which is why pharmacists and patients frequently ask whether the two interact. Dutasteride is also available as a fixed-dose combination with tamsulosin (Jalyn), which adds another CYP3A4 substrate to the regimen and is addressed separately below.

Dutasteride's metabolic pathway: CYP3A4

According to the FDA-approved Avodart labeling, dutasteride is extensively metabolized in humans, principally by CYP3A4, with a smaller contribution from CYP3A5. It reaches peak plasma concentration a few hours after an oral dose, is highly protein-bound, and has an unusually long terminal half-life (on the order of weeks at steady state), which reflects slow release from tissue rather than slow liver clearance. The label states that dutasteride did not produce clinically meaningful inhibition of several major CYP enzymes at therapeutic concentrations, including CYP2C9, the minor pathway rosuvastatin uses.

Because dutasteride is a CYP3A4 substrate, drugs that strongly inhibit CYP3A4 (certain azole antifungals, some HIV protease inhibitors, some macrolide antibiotics) can raise dutasteride exposure. The label describes an increase in dutasteride exposure with moderate CYP3A4 inhibitors such as verapamil or diltiazem; strong inhibitors were not formally studied for this pair but would be expected to have a larger effect based on the mechanism. Rosuvastatin has no CYP3A4 inhibitory activity, so it is not expected to raise dutasteride levels. Readers who want the exact fold-change figures from the current label should verify them against the most recent Avodart prescribing information rather than relying on any secondary summary, including this one.

Rosuvastatin's disposition: transporters, not enzymes

Rosuvastatin is unusual among statins because only a minority of an oral dose is metabolized by CYP enzymes (mainly CYP2C9, to a minor active metabolite); most of the dose is eliminated unchanged. This is part of why rosuvastatin is considered less prone to CYP-mediated interactions than statins that depend heavily on CYP3A4, such as simvastatin and lovastatin.

The clinically important vulnerability for rosuvastatin is at membrane transporters. Rosuvastatin is a substrate of the hepatic uptake transporters OATP1B1 and OATP1B3, and of the efflux transporter BCRP. Drugs that inhibit these transporters, cyclosporine and certain protease-inhibitor combinations are the label examples, can substantially raise rosuvastatin plasma levels and increase the risk of muscle toxicity, which is why the Crestor label caps the dose when those drugs are co-prescribed.

Dutasteride has no documented activity at OATP1B1, OATP1B3, or BCRP. The Avodart label does not describe transporter inhibition as part of its pharmacokinetic profile, and this review found no published mechanistic study showing dutasteride affecting these transporters. That absence supports, but does not by itself prove beyond doubt, that dutasteride cannot raise rosuvastatin exposure through this route.

The following is the load-bearing summary of this page:

Dutasteride is cleared by hepatic CYP3A4; rosuvastatin's plasma levels depend on OATP1B1/OATP1B3 and BCRP transporters rather than CYP3A4, and dutasteride is not described as an inhibitor of any of those transporters in its FDA labeling. Because the two drugs act on non-overlapping clearance pathways, current FDA labels for both products list no interaction between them, and standard interaction references classify the combination as having no expected clinically significant effect on either drug's levels, a conclusion based on mechanism and labeling review rather than a dedicated dutasteride-rosuvastatin interaction trial.

What is established, what is plausible, and what is not established

HRX:framework Evidence-status interaction assessment

Claim	Status	Basis	What a clinician or pharmacist should still verify
Dutasteride is a CYP3A4/CYP3A5 substrate	Established	FDA-approved Avodart labeling	Current label version, since labeling is periodically updated
Rosuvastatin is minimally CYP-metabolized and largely excreted unchanged	Established	FDA-approved Crestor labeling	N/A for this pair; relevant mainly to other interacting drugs
Rosuvastatin exposure depends on OATP1B1/OATP1B3/BCRP transporter activity	Established	FDA-approved Crestor labeling	Whether the patient is taking any other OATP/BCRP inhibitor (cyclosporine, certain antivirals)
Dutasteride does not inhibit CYP2C9 or major CYP enzymes at therapeutic doses	Established (in vitro data per label)	FDA-approved Avodart labeling	Whether newer post-marketing data has changed this characterization
Dutasteride does not inhibit OATP1B1, OATP1B3, or BCRP	Plausible, supported by absence of listed interaction	Absence of transporter inhibition data in the Avodart label	No dedicated transporter-inhibition study for dutasteride was located in this review; confirm against current literature if this matters clinically for a specific patient
No dose adjustment is needed for either drug when co-prescribed	Established per current labeling	Neither FDA label lists the other drug as requiring dose modification	Re-check both labels directly, since labeling can change
Adding dutasteride does not increase statin-associated muscle symptom risk	Plausible, not directly established by a dedicated trial	Mechanistic reasoning (no shared toxicity pathway) plus absence of a documented myotoxic signal for dutasteride	A head-to-head or pharmacovigilance study specifically evaluating this combination was not identified; if a patient develops new muscle symptoms after starting both drugs, do not assume the combination is exonerating, evaluate as you would any statin myopathy concern
Specific numeric interaction figures (fold-changes in AUC, percentage PSA suppression, trial adverse-event rates)	Not verified in this review	Cited in older secondary summaries but not independently confirmed against a current primary source here	Verify any specific number against the current FDA label or the original trial publication before using it for a clinical decision

Monitoring: what actually needs to be tracked

Nothing about combining these two drugs adds a new lab test. Standard monitoring for each drug individually is what matters:

For rosuvastatin: a baseline lipid panel and baseline transaminases, with a follow-up lipid check some weeks after starting or adjusting the dose, and periodic rechecks per the treating clinician's usual practice. The FDA's 2012 safety communication on statins removed the requirement for routine periodic liver-enzyme monitoring, though many clinicians still check periodically. Creatine kinase should be checked only if the patient develops new muscle pain, tenderness, or weakness, not as a routine screen.

For dutasteride: the key monitoring point is PSA interpretation, not liver or muscle labs. Dutasteride lowers serum PSA, and clinicians are instructed to adjust (commonly by doubling) a measured PSA value for comparison against normal ranges in men not taking a 5-alpha reductase inhibitor. A confirmed PSA rise while on dutasteride, even if the adjusted value looks "normal," should prompt urologic follow-up rather than reassurance, since it can signal higher-grade disease. The exact magnitude and timeline of PSA suppression should be confirmed against the current Avodart label rather than assumed from memory.

Neither drug requires additional renal monitoring specifically because of this combination.

Where a statin actually does interact with dutasteride-class drugs

The contrast is useful. Simvastatin and lovastatin are heavily dependent on CYP3A4 for clearance, so strong or moderate CYP3A4 inhibitors (certain azole antifungals, macrolides, some HIV medications, and grapefruit juice in large amounts) can meaningfully raise their levels and raise rhabdomyolysis risk, which is why the simvastatin label carries specific dose caps and contraindications with strong CYP3A4 inhibitors. Rosuvastatin avoids most of that risk because it does not rely on CYP3A4. Dutasteride is a CYP3A4 substrate itself, but it is not described in its label as a CYP3A4 inhibitor, so it does not raise the levels of CYP3A4-dependent statins the way a true inhibitor would. This is a meaningful distinction: being metabolized by an enzyme is not the same as inhibiting it, and only inhibition would create a two-way interaction risk.

Special situations that deserve more attention than the drug pair itself

Older patients. Statin-associated muscle symptoms are reported more often in older adults, and hepatic CYP3A4 activity can decline with age, which may slow dutasteride clearance somewhat. Neither of these is a drug-drug interaction between dutasteride and rosuvastatin; they are independent age-related factors that a clinician may want to account for when choosing a starting statin dose.

Patients of East Asian ancestry. The Crestor label recommends a lower starting dose in Asian patients because of differences in rosuvastatin exposure linked to OATP1B1 genetic variation (the SLCO1B1 polymorphism). This is a rosuvastatin-specific dosing consideration and is unrelated to dutasteride, but it is relevant to overall regimen safety and should not be missed simply because the focus is on the dutasteride question.

Patients on dutasteride plus tamsulosin (Jalyn). Tamsulosin is also metabolized by CYP3A4 (and CYP2D6). Adding a strong CYP3A4 inhibitor to a regimen that already contains dutasteride and tamsulosin could raise levels of both BPH drugs at once, even though rosuvastatin itself is not the source of that risk. Anyone managing all three drugs together should stay alert to CYP3A4 inhibitors added later for unrelated conditions (a new antifungal or antibiotic, for example).

When to seek care rather than wait

New or worsening muscle pain, weakness, or dark urine while on a statin warrants prompt evaluation regardless of what other drugs are on board, since these can signal rare but serious muscle breakdown (rhabdomyolysis). A confirmed rise in PSA while on dutasteride should be evaluated by the prescribing clinician or a urologist rather than dismissed as reassuring because it is still within a "normal" numeric range. This article does not provide individualized dosing or diagnosis; decisions about starting, stopping, or adjusting either drug belong to the prescribing clinician, who has the patient's full medication list, kidney and liver function, and cardiovascular risk profile.

Frequently asked questions

Can I take Avodart with rosuvastatin?

There is no clinically significant pharmacokinetic interaction described in either drug's FDA labeling. The two drugs are cleared through different pathways, dutasteride by CYP3A4, rosuvastatin mainly by biliary excretion and transporter handling, so no dose adjustment is listed as necessary for this combination. This reflects mechanism and labeling review, not a dedicated interaction trial in this specific pair.

Does dutasteride affect cholesterol levels?

Dutasteride is not described in its labeling as having a lipid-lowering or lipid-raising effect; it works on 5-alpha reductase, an unrelated pathway. Anyone relying on a specific numeric claim about lipid changes in a dutasteride trial should verify it against the primary trial publication rather than a secondary summary.

Should dutasteride and rosuvastatin be taken at different times of day?

No timing separation is described as necessary in either label, since there is no absorption or metabolic competition between them.

Can rosuvastatin increase dutasteride side effects, or vice versa?

Rosuvastatin does not inhibit CYP3A4, the enzyme dutasteride depends on for clearance, so it is not expected to raise dutasteride levels. Dutasteride is not described as inhibiting the OATP or BCRP transporters that control rosuvastatin levels, so it is not expected to raise rosuvastatin exposure either. Neither claim has been tested in a dedicated interaction trial specific to this pair.

What statins are considered lower risk to combine with dutasteride?

Statins that do not rely heavily on CYP3A4 for clearance, such as rosuvastatin and pravastatin, carry less theoretical interaction risk with any CYP3A4 substrate. This is a mechanistic inference from each drug's labeling rather than a comparative trial result.

Will dutasteride affect my PSA test results?

Yes. Dutasteride lowers PSA, and clinicians typically adjust the measured value for comparison against untreated ranges. The exact magnitude and timing should be confirmed with the prescribing clinician using current labeling, since this affects how a rising PSA on dutasteride should be interpreted.

Do I need extra liver or muscle tests because I'm taking both drugs?

No additional testing is described as necessary specifically because of this combination. Standard statin monitoring (baseline transaminases, periodic lipid checks, CK only if symptomatic) and standard dutasteride monitoring (adjusted PSA interpretation) are what apply.

References

U.S. Food and Drug Administration. Avodart (dutasteride) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/021319s032lbl.pdf, verify against the current label version before relying on specific numeric figures.
U.S. Food and Drug Administration. Zocor (simvastatin) prescribing information: drug interactions and dose limitations. https://www.accessdata.fda.gov/drugsatfda_docs/label/2012/019766s085lbl.pdf
U.S. Food and Drug Administration. Flomax (tamsulosin hydrochloride) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2009/020579s026lbl.pdf