PIRFENIDONE Drug Interactions: What You Need to Know

INTERACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling: Liver Enzyme Elevations and Drug-Induced Liver Injury [see Warnings and Precautions (5.1) ]

Photosensitivity

Reaction or Rash [see Warnings and Precautions (5.2) ]

Gastrointestinal

Disorders [see Warnings and Precautions (5.3) ] Moderate (e.g., ciprofloxacin) and strong inhibitors of CYP1A2 (e.g., fluvoxamine) increase systemic exposure of pirfenidone and may alter the adverse reaction profile of pirfenidone. Discontinue fluvoxamine prior to administration of pirfenidone or reduce to 267 mg three times a day. Consider dosage reduction with use of ciprofloxacin. (7.1)

7.1 CYP1A2 Inhibitors Pirfenidone is metabolized primarily (70% to 80%) via CYP1A2 with minor contributions from other CYP isoenzymes including CYP2C9, 2C19, 2D6 and 2E1. Strong CYP1A2 Inhibitors The concomitant administration of pirfenidone and fluvoxamine or other strong CYP1A2 inhibitors (e.g., enoxacin) is not recommended because it significantly increases exposure to pirfenidone <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span>. Use of fluvoxamine or other strong CYP1A2 inhibitors should be discontinued prior to administration of pirfenidone and avoided during pirfenidone treatment. In the event that fluvoxamine or other strong CYP1A2 inhibitors are the only drug of choice, dosage reductions are recommended. Monitor for adverse reactions and consider discontinuation of pirfenidone as needed [ see Dosage and Administration (2.4) ] . Moderate CYP1A2 Inhibitors Concomitant administration of pirfenidone and ciprofloxacin (a moderate inhibitor of CYP1A2) moderately increases exposure to pirfenidone <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> . If ciprofloxacin at the dosage of 750 mg twice daily cannot be avoided, dosage reductions are recommended <span class="opacity-50 text-xs">[see Dosage and Administration (2.4) ]</span>. Monitor patients closely when ciprofloxacin is used at a dosage of 250 mg or 500 mg once daily. Concomitant CYP1A2 and other CYP Inhibitors Agents or combinations of agents that are moderate or strong inhibitors of both CYP1A2 and one or more other CYP isoenzymes involved in the metabolism of pirfenidone (i.e. CYP2C9, 2C19, 2D6, and 2E1) should be discontinued prior to and avoided during pirfenidone treatment.

7.2 CYP1A2 Inducers The concomitant use of pirfenidone and a CYP1A2 inducer may decrease the exposure of pirfenidone and this may lead to loss of efficacy. Therefore, discontinue use of strong CYP1A2 inducers prior to pirfenidone treatment and avoid the concomitant use of pirfenidone and a strong CYP1A2 inducer <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3) ]</span> .

None. None.

AND PRECAUTIONS Elevated liver enzymes and drug-induced liver injury: ALT, AST, and bilirubin elevations have occurred with pirfenidone including cases of drug-induced liver injury. In the postmarketing setting, non-serious and serious cases of drug-induced liver injury, including severe liver injury with fatal outcomes, have been reported. Monitor ALT, AST, and bilirubin before and during treatment. Temporary dosage reductions or discontinuations may be required. (2.1 , 5.1 ) Photosensitivity and rash: Photosensitivity and rash have been noted with pirfenidone. Avoid exposure to sunlight and sunlamps. Wear sunscreen and protective clothing daily. Temporary dosage reductions or discontinuations may be required. ( 5.2 )

Severe Cutaneous Adverse

Reactions (SCAR): Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reactions with eosinophilia and systemic symptoms (DRESS) have been reported in association with the use of pirfenidone in the postmarketing setting. Interrupt pirfenidone in case of signs or symptoms of SCAR. Permanently discontinue pirfenidone if a SCAR is confirmed. ( 5.3 ) Gastrointestinal disorders: Nausea, vomiting, diarrhea, dyspepsia, gastro­-esophageal reflux disease, and abdominal pain have occurred with pirfenidone. Temporary dosage reductions or discontinuations may be required. ( 5.4 )

5.1 Elevated Liver Enzymes and Drug-Induced Liver Injury Cases of drug-induced liver injury (DILI) have been observed with pirfenidone. In the postmarketing period, non-serious and serious cases of DILI, including severe liver injury with fatal outcome, have been reported. Patients treated with pirfenidone 2403 mg/day in three Phase 3 trials had a higher incidence of elevations in ALT or AST ≥3x ULN than placebo patients (3.7% vs 0.8%, respectively). Elevations ≥10xULN in ALT or AST occurred in 0.3% of patients in the Esbriet 2403 mg/day group and in 0.2% of patients in the placebo group. Increases in ALT and AST ≥3x ULN were reversible with dose modification or treatment discontinuation. Conduct liver function tests (ALT, AST, and bilirubin) prior to the initiation of therapy with pirfenidone, monthly for the first 6 months, every 3 months thereafter, and as clinically indicated. Measure liver function tests promptly in patients who report symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine, or jaundice. Dosage modification or interruption may be necessary for liver enzyme elevations [ see Dosage and Administration (2.1, 2.3)].

5.2 Photosensitivity Reaction or Rash Patients treated with pirfenidone 2403 mg/day in the three Phase 3 studies had a higher incidence of photosensitivity reactions (9%) compared with patients treated with placebo (1%). The majority of the photosensitivity reactions occurred during the initial 6 months. Instruct patients to avoid or minimize exposure to sunlight (including sunlamps), to use a sunblock (SPF 50 or higher), and to wear clothing that protects against sun exposure. Additionally, instruct patients to avoid concomitant medications known to cause photosensitivity. Dosage reduction or discontinuation may be necessary in some cases of photosensitivity reaction or rash <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.3 )]</span>.

5.3 Gastrointestinal Disorders In the clinical studies, gastrointestinal events of nausea, diarrhea, dyspepsia, vomiting, gastro-esophageal reflux disease, and abdominal pain were more frequently reported by patients in the pirfenidone treatment groups than in those taking placebo. Dosage reduction or interruption for gastrointestinal events was required in 18.5% of patients in the 2403 mg/day group, as compared to 5.8% of patients in the placebo group; 2.2% of patients in the pirfenidone 2403 mg/day group discontinued treatment due to a gastrointestinal event, as compared to 1.0% in the placebo group. The most common (&gt;2%) gastrointestinal events that led to dosage reduction or interruption were nausea, diarrhea, vomiting, and dyspepsia. The incidence of gastrointestinal events was highest early in the course of treatment (with highest incidence occurring during the initial 3 months) and decreased over time. Dosage modifications may be necessary in some cases of gastrointestinal adverse reactions <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.3 )]</span>.

5.4 Gastrointestinal Disorders In the clinical studies, gastrointestinal events of nausea, diarrhea, dyspepsia, vomiting, gastro-esophageal reflux disease, and abdominal pain were more frequently reported by patients in the pirfenidone treatment groups than in those taking placebo. Dosage reduction or interruption for gastrointestinal events was required in 18.5% of patients in the 2403 mg/day group, as compared to 5.8% of patients in the placebo group; 2.2% of patients in the pirfenidone 2403 mg/day group discontinued treatment due to a gastrointestinal event, as compared to 1.0% in the placebo group. The most common (&gt;2%) gastrointestinal events that led to dosage reduction or interruption were nausea, diarrhea, vomiting, and dyspepsia. The incidence of gastrointestinal events was highest early in the course of treatment (with highest incidence occurring during the initial 3 months) and decreased over time. Dosage modifications may be necessary in some cases of gastrointestinal adverse reactions <span class="opacity-50 text-xs">[see Dosage and Administration (2.3) ]</span>.