Rosuvastatin (Crestor) Drug-Drug Interactions: A Complete Clinical Profile

How Rosuvastatin Works and Why Its Interaction Profile Differs From Other Statins

Rosuvastatin inhibits HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis, with a binding affinity roughly 4-fold greater than atorvastatin. That pharmacodynamic story is shared across the statin class. The pharmacokinetic story is not.

Most statin interactions stem from CYP3A4 competition. Atorvastatin and simvastatin depend heavily on CYP3A4 for first-pass metabolism, making them vulnerable to azole antifungals, macrolide antibiotics, and grapefruit juice. Rosuvastatin sidesteps this pathway almost entirely. Approximately 10% of its clearance involves CYP2C9, with a minor contribution from CYP2C19 1. The remaining 90% is eliminated through hepatic uptake via organic anion transporting polypeptide 1B1 (OATP1B1, encoded by SLCO1B1) and efflux via breast cancer resistance protein (BCRP, encoded by ABCG2) 2.

This transporter-dependent clearance means rosuvastatin's danger zone is different. The drugs that spike its plasma levels are not CYP3A4 inhibitors. They are OATP1B1 and BCRP inhibitors. Clinicians who memorize the CYP3A4 statin list and assume rosuvastatin is "clean" risk missing serious interactions with immunosuppressants, antiretrovirals, and direct-acting hepatitis C antivirals.

The FDA-approved prescribing information states: "Rosuvastatin is not a substrate for CYP3A4 metabolism; therefore, drugs that inhibit CYP3A4 are not expected to affect the plasma concentration of rosuvastatin" 3. That sentence reassures. The next sentence should give pause: "Inhibitors of transporter proteins may increase systemic exposure of rosuvastatin."

Contraindicated Combination: Cyclosporine

Cyclosporine with rosuvastatin is contraindicated at any dose. Full stop.

A pharmacokinetic study in cardiac transplant recipients showed that cyclosporine increased rosuvastatin AUC by 7.1-fold and C_max by 10.6-fold 3. This magnitude of exposure increase puts patients at unacceptable risk for rhabdomyolysis. The mechanism involves dual inhibition: cyclosporine blocks OATP1B1-mediated hepatic uptake and simultaneously inhibits BCRP-mediated biliary and intestinal efflux 4.

For transplant patients who require statin therapy, the 2018 American Heart Association/American College of Cardiology cholesterol guideline recommends pravastatin or fluvastatin as first-line alternatives, both of which show smaller magnitude interactions with cyclosporine 5. Pitavastatin at 1 mg daily is another option with limited cyclosporine interaction data but a favorable transporter profile.

Dose-Capped Interactions: The 5 mg and 10 mg Thresholds

Several drugs raise rosuvastatin exposure enough to require a hard dose ceiling but not enough to warrant contraindication. These thresholds are not suggestions. They are FDA-labeled requirements.

Gemfibrozil (cap: 10 mg/day). Gemfibrozil inhibits OATP1B1 and CYP2C9 simultaneously. Co-administration raised rosuvastatin AUC by 1.9-fold in healthy volunteers 3. A pooled safety analysis of 37,000+ statin-treated patients reported that fibrate co-administration increased myopathy incidence from 0.04% to 0.12%, a 3-fold relative increase, with gemfibrozil accounting for the majority of cases 6. The 2018 ACC/AHA guideline specifically recommends fenofibrate over gemfibrozil when combining a fibrate with any statin 5.

Atazanavir/ritonavir (cap: 10 mg/day). This HIV protease inhibitor combination increased rosuvastatin AUC by 3.1-fold and C_max by 7.0-fold 7. Ritonavir inhibits BCRP while atazanavir inhibits OATP1B1, producing an additive transporter blockade. Lopinavir/ritonavir produces a 2.1-fold AUC increase and carries the same 10 mg cap 3.

Sofosbuvir/velpatasvir and related hepatitis C regimens (cap: 10 mg/day). Velpatasvir and ledipasvir inhibit BCRP and OATP1B1/1B3. Post-marketing reports documented multiple cases of unexpected rhabdomyolysis in patients on rosuvastatin 20 mg who started sofosbuvir/velpatasvir, prompting an FDA safety communication in 2018 8. The prescribing information now mandates a 10 mg ceiling.

Darolutamide (cap: 5 mg/day). This non-steroidal androgen receptor inhibitor, used in prostate cancer, inhibits BCRP and raised rosuvastatin AUC by 5.2-fold in a phase I study. The 5 mg cap is among the most restrictive for any rosuvastatin interaction 3.

Clinically Significant Interactions Without Dose Caps

Not every meaningful interaction triggers a labeled dose restriction. Several combinations require heightened monitoring or timing adjustments rather than dose ceilings.

Warfarin. Rosuvastatin modestly potentiates warfarin's anticoagulant effect. In a controlled study, rosuvastatin 40 mg daily increased warfarin's INR by approximately 19% relative to baseline 3. The mechanism likely involves competition for CYP2C9, which metabolizes both S-warfarin and (minimally) rosuvastatin. The ACC recommends checking INR within 7 days of starting or dose-adjusting rosuvastatin in patients on stable warfarin therapy 5. A 1.5 to 2 point INR rise is typical at high rosuvastatin doses.

Aluminum/magnesium hydroxide antacids. Co-administration reduces rosuvastatin C_max by 50% and AUC by 20% due to physical adsorption in the GI tract 3. The FDA label recommends giving the antacid at least 2 hours after rosuvastatin. This interaction is pharmacokinetically significant but often ignored in practice. Proton pump inhibitors and H2 blockers do not share this adsorption effect and can be dosed freely.

Fenofibrate. Unlike gemfibrozil, fenofibrate does not inhibit OATP1B1. Co-administration with rosuvastatin produced no clinically meaningful change in AUC in a crossover trial 9. The combination is considered safe without a dose cap, though the general myopathy risk of any statin-fibrate pair still warrants monitoring of creatine kinase if symptoms develop.

Ezetimibe. Ezetimibe 10 mg with rosuvastatin showed no pharmacokinetic interaction in either direction 3. The IMPROVE-IT trial (N=18,144) demonstrated the clinical benefit of adding ezetimibe to statin therapy, with a 6.4% relative reduction in major CV events at 7 years 10. This combination is pharmacokinetically clean and guideline-endorsed.

Pharmacogenomic Interactions: SLCO1B1 and ABCG2 Variants

Genetic variation in the same transporters that mediate drug-drug interactions also mediates gene-drug interactions. The line between the two categories blurs in patients carrying reduced-function alleles who then receive an interacting medication.

The SLCO1B1 c.521T>C variant (rs4149056) reduces OATP1B1 transporter activity. Homozygous carriers (CC genotype, prevalence ~2% in European-ancestry populations) show a 65% increase in rosuvastatin AUC compared to wild-type 11. The Clinical Pharmacogenetics Implementation Consortium (CPIC) 2022 guideline recommends prescribing rosuvastatin at <20 mg/day for SLCO1B1 poor-function carriers and avoiding co-administration with OATP1B1-inhibiting drugs when possible 12.

The ABCG2 c.421C>A variant (rs2231142) reduces BCRP efflux. Carriers show a 1.4 to 2.4-fold increase in rosuvastatin AUC depending on zygosity 12. When a patient carries both SLCO1B1 521CC and ABCG2 421CA/AA, the combined effect on rosuvastatin exposure can approximate what cyclosporine does pharmacologically. CPIC recommends a 50% dose reduction and avoidance of interacting drugs in these double-risk genotype patients.

Dr. Teri Klein, co-principal investigator of PharmGKB at Stanford University, has noted: "Pharmacogenomic testing for SLCO1B1 before statin initiation is one of the most actionable gene-drug pairs in clinical medicine today" 12.

OATP1B1 and BCRP Inhibitors: A Unified Reference Table

Because rosuvastatin interactions cluster around two transporters, clinicians benefit from thinking in transporter terms rather than memorizing individual drug pairs. The following drugs inhibit OATP1B1, BCRP, or both in vivo at clinically relevant concentrations.

OATP1B1 inhibitors include cyclosporine, gemfibrozil, eltrombopag, atazanavir, rifampin (single dose, paradoxically; chronic dosing induces OATP1B1), and eluxadoline 2. BCRP inhibitors include cyclosporine, ritonavir, eltrombopag, darolutamide, and velpatasvir 3. Cyclosporine and eltrombopag inhibit both transporters, explaining their outsized effect on rosuvastatin levels.

The 2020 FDA Draft Guidance on Drug Interaction Studies recommends that sponsors evaluate new molecular entities for OATP1B1 and BCRP inhibition using rosuvastatin as a probe substrate 13. This means the list of labeled rosuvastatin interactions will continue to grow as new oncology and antiviral agents reach market.

Interactions That Do Not Occur: Common Misconceptions

One practical advantage of rosuvastatin's CYP independence is a clean interaction profile with several drug classes that cause problems for atorvastatin and simvastatin.

Azole antifungals (fluconazole, itraconazole, ketoconazole). These potent CYP3A4 inhibitors increase simvastatin AUC by up to 20-fold but have no clinically meaningful effect on rosuvastatin 1. Patients who need prolonged antifungal therapy may be safer on rosuvastatin or pravastatin than on CYP3A4-dependent statins.

Macrolide antibiotics (erythromycin, clarithromycin). Erythromycin increased simvastatin AUC by 3.4-fold in a classic interaction study, but rosuvastatin AUC was unchanged 3. Azithromycin, a weak CYP3A4 inhibitor, poses negligible risk with any statin.

Grapefruit juice. The furanocoumarins in grapefruit irreversibly inhibit intestinal CYP3A4. Because rosuvastatin does not undergo significant CYP3A4 metabolism, grapefruit consumption requires no restriction 1.

Diltiazem and verapamil. Both calcium channel blockers inhibit CYP3A4 and P-glycoprotein. The FDA label for simvastatin mandates a dose cap with both. Rosuvastatin has no such restriction 3. This distinction matters for the cardiology patient on a rate-control strategy who also needs high-intensity statin therapy.

Clinical Context: Rosuvastatin in Primary Prevention and Polypharmacy

The JUPITER trial (N=17,802) demonstrated that rosuvastatin 20 mg daily reduced major cardiovascular events by 44% (HR 0.56; 95% CI, 0.46 to 0.69; P<0.00001) in adults with LDL cholesterol <130 mg/dL and high-sensitivity C-reactive protein ≥2.0 mg/L over a median 1.9 years of follow-up 14. That trial established rosuvastatin as a primary prevention tool in a population not previously considered statin-eligible.

The patients who benefit most from rosuvastatin are often the same patients on complex multi-drug regimens: transplant recipients, people living with HIV, patients with chronic hepatitis C, and older adults with metabolic syndrome on 8 or more medications. In the JUPITER population, the median age was 66, and 41% of participants were on antihypertensives at baseline 14.

Dr. Paul Ridker, the JUPITER principal investigator, stated in the original publication: "We found that in apparently healthy persons without hyperlipidemia but with elevated high-sensitivity C-reactive protein levels, rosuvastatin significantly reduced the incidence of major cardiovascular events" 14. That finding makes the interaction profile not an academic exercise but a daily clinical calculation for millions of patients.

Monitoring Protocol for High-Risk Combinations

When rosuvastatin must be co-prescribed with an OATP1B1 or BCRP inhibitor that carries a dose cap (not cyclosporine, which is contraindicated), the following monitoring sequence reflects current evidence and consensus.

Baseline labs before co-prescription: creatine kinase (CK), alanine aminotransferase (ALT), serum creatinine with estimated GFR. Renal impairment (eGFR <30 mL/min/1.73 m²) independently raises rosuvastatin exposure by 3-fold and compounds transporter-mediated interactions 3.

At 4 to 6 weeks post co-initiation: repeat ALT and CK. Ask specifically about muscle pain, tenderness, and dark urine. The 2018 ACC/AHA guideline notes that routine CK monitoring is not required for statins alone but is appropriate when risk-multiplying interactions are present 5. If CK exceeds 10 times the upper limit of normal or the patient develops unexplained muscle symptoms with any CK elevation, discontinue rosuvastatin immediately and evaluate for rhabdomyolysis.

At 3 months and annually: repeat lipid panel and hepatic function. Confirm the rosuvastatin dose remains at or below the labeled cap. Automated interaction-checking software flags these combinations at dispensing, but dose caps entered into the prescribing record at initiation may be overridden during refills if the interacting drug was started later.

Rosuvastatin 5 mg daily achieves approximately 38% LDL reduction; 10 mg achieves approximately 43% 3. For patients capped at these doses who need greater LDL lowering, add ezetimibe 10 mg (no interaction, additional 18 to 20% LDL reduction) or consider a PCSK9 inhibitor.