Pirfemac

Uses

Pirfemac is used for adults for the treatment of mild to moderate Idiopathic Pulmonary Fibrosis (IPF).

Pirfemac is also used to associated treatment for these conditions: Mild Idiopathic Pulmonary Fibrosis, Moderate Idiopathic Pulmonary Fibrosis

How Pirfemac works

Although the precise mechanism of action of pirfenidone and its specific molecular targets have yet to be elucidated, the molecule has demonstrated anti-fibrotic, anti-inflammatory, and antioxidant activity. One vital anti-fibrotic mechanism involves suppression of TGF-β1 (transforming growth factor-β1), a key cytokine involved in fibrogenesis and extracellular matrix production.

There is also evidence to suggest that pirfenidone has the ability to downregulate the expression of potent pro-inflammatory cytokines including TNF-α, interleukin-1, and interferon gamma. In animal models, pirfenidone can inhibit both the influx of inflammatory cells and the increased pulmonary vascular permeability induced by bleomycin.

Dosage

Pirfemac dosage

Treatment with Pirfemac should be initiated and supervised by specialist physicians experienced in the diagnosis and treatment of IPF.

Adults: Upon initiating treatment, the dose should be titrated to the recommended daily dose of nine capsules per day over a 14-day period as follows:

• Days 1 to 7: one capsule, three times a day (801 mg/day)
• Days 8 to 14: two capsules, three times a day (1602 mg/day)
• Day 15 onward: three capsules, three times a day (2403 mg/day)

The recommended daily dose of Pirfemac for patients with IPF is three 267 mg capsules three times a day with food for a total of 2403 mg/day. Doses above 2403 mg/day are not recommended for any patient. Patients who miss 14 consecutive days or more of Pirfemac treatment should re-initiate therapy by undergoing the initial 2-week titration regimen up to the recommended daily dose. For treatment interruption of less than 14 consecutive days, the dose can be resumed at the previous recommended daily dose without titration.

Dose adjustments and other considerations for safe use: Gastrointestinal events: In patients who experience intolerance to therapy due to gastrointestinal side effects, patients should be reminded to take the medicinal product with food. If symptoms persist Pirfemac may be reduced to 1-2 capsules (267 mg – 534 mg) 2-3 times/day with food with re-escalation to the recommended daily dose as tolerated. If symptoms continue, patients may be instructed to interrupt treatment for 1 to 2 weeks to allow symptoms to resolve.

Photosensitivity reaction or rash: Patients who experience a mild to moderate photosensitivity reaction or rash should be reminded of the instruction to use a sunblock daily and to avoid sun exposure. The dose of Pirfemac may be reduced to 3 capsules/day (1 capsule three times a day). If the rash persists after 7 days, Pirfemac should be discontinued for 15 days, with re-escalation to the recommended daily dose in the same manner as the dose escalation period.

Patients who experience severe photosensitivity reaction or rash should be instructed to interrupt the dose and to seek medical advice. Once the rash has resolved, Pirfemac may be re-introduced and re-escalated up to the recommended daily dose at the discretion of the physician.

Hepatic function: In the event of significant elevation of alanine and/or aspartate aminotransferases (ALT/AST) with or without bilirubin elevation, the dose of Pirfemac should be adjusted or treatment discontinued according to the guidelines.

Side Effects

The safety of Pirfemac has been evaluated in clinical studies including 1345 healthy volunteers and patients.

The most commonly reported (10%) adverse reactions during clinical study experience with Pirfemac at a dose of 2403 mg/day compared to placebo, respectively, were nausea (32.8% versus 13.3%), rash (28.7% versus 8.6%), fatigue (22.3% versus 13.3%), diarrhoea (21.7% versus 13.5%), dyspepsia (16.8% versus 5.5%), and photosensitivity reaction (12.2% versus 1.7%).

Serious adverse reactions were recorded at similar frequencies among patients treated with 2403 mg/day of Pirfemac and placebo in clinical studies.

The adverse reactions reported at a frequency of 2% in 345 patients receiving Pirfemac at the recommended dose of 2403 mg/day in two pivotal Phase 3 studies. Adverse reactions from post-marketing experience are also listed. Adverse reactions are listed by System Organ Class (SOC) and within each frequency grouping the adverse reactions are presented in order of decreasing seriousness.

Toxicity

Generally well tolerated with the most frequent side effects reported being photosensitivity rash and gastrointestinal symptoms.

Food Interaction

• Take at the same time every day.
• Take with food. This may reduce the adverse effects of nausea and dizziness. Food also impacts the bioavailability of pirfenidone.

[Moderate] ADJUST DOSING INTERVAL: Food significantly slows the rate but only modestly reduces the extent of absorption of pirfenidone.

In healthy, older adult volunteers aged 50 to 66 years, administration of a single 801 mg oral dose of pirfenidone in the fed state resulted in an approximately 50% reduction in peak plasma concentration (Cmax) and a 15% to 20% reduction in systemic exposure (AUC) compared to administration in the fasted state.

Median time to reach peak concentration (Tmax) increased from 0.5 hours to 3 hours with food.

Less nausea and dizziness were observed in fed subjects compared to fasted subjects.

GENERALLY AVOID: Consumption of grapefruit juice is associated with inhibition of CYP450 1A2 and may increase the plasma concentrations of pirfenidone, which is primarily metabolized by the isoenzyme.

GENERALLY AVOID: Cigarette smoking may reduce pirfenidone exposure due to induction of CYP450 1A2, the isoenzyme primarily responsible for the metabolic clearance of pirfenidone.

Following a single 801 mg oral dose of pirfenidone in 25 smokers and 25 healthy nonsmokers, the Cmax and AUC of pirfenidone in smokers were 68% and 46% of those in nonsmokers, respectively.

MANAGEMENT: Pirfemac should be administered with food to reduce the likelihood of dizziness and gastrointestinal side effects such as nausea, diarrhea, dyspepsia, and vomiting.

Patients who experience intolerance to therapy due to these adverse events should be reminded to take pirfenidone with food.

If symptoms do not improve, or they worsen in severity, a dosage reduction or discontinuation of therapy may be warranted.

Patients should be advised to avoid consumption of grapefruit and grapefruit juice during treatment with pirfenidone.

Cigarette smoking should also be avoided during therapy to prevent reduced exposure to pirfenidone.

Pirfemac Drug Interaction

Unknown: contained in alcoholic beverages , umeclidinium / vilanterol, aspirin, citalopram, albuterol / ipratropium, ubiquinone, diltiazem, apixaban, heparin, escitalopram, atorvastatin, metoprolol, metoprolol, polyethylene glycol 3350, acetylcysteine, acetaminophen, budesonide / formoterol, cyanocobalamin, ascorbic acid, cholecalciferol

Pirfemac Disease Interaction

Moderate: hepatic impairment, renal impairment, smoking

Volume of Distribution

The steady-state volume of distribution following oral administration is approximately 70L.

Elimination Route

Rapidly absorbed following oral administration.

Half Life

2-2.5 hours

Pregnancy & Breastfeeding use

Pregnancy: There are no data from the use of Pirfemac in pregnant women.

In animals placental transfer of pirfenidone and/or its metabolites occurs with the potential for accumulation of pirfenidone and/or its metabolites in amniotic fluid.

At high doses (1000 mg/kg/day) rats exhibited prolongation of gestation and reduction in fetal viability.

As a precautionary measure, it is preferable to avoid the use of Pirfemac during pregnancy.

Lactation: It is unknown whether pirfenidone or its metabolites are excreted in human milk. Available pharmacokinetic data in animals have shown excretion of pirfenidone and/or its metabolites in milk with the potential for accumulation of pirfenidone and/or its metabolites in milk. A risk to the suckling child cannot be excluded. A decision must be made whether to discontinue breast-feeding or to discontinue from Pirfemac therapy, taking into account the benefit of breast-feeding for the child and the benefit of Pirfemac therapy for the mother.

Fertility: No adverse effects on fertility were observed in preclinical studies

Effects on ability to drive and use machines: No studies on the effects of the ability to drive and use machines have been performed. Pirfemac may cause dizziness and fatigue, which could influence the ability to drive or use machines.

Contraindication

Hypersensitivity to the active substance or to any of the excipients.

• concomitant use of fluvoxamine,
• severe hepatic impairment or end stage liver disease,
• severe renal impairment (CrCl <30 ml/min) or end stage renal disease requiring dialysis

Hepatic function: Elevations in ALT and AST >3 × upper limit of normal (ULN) have been reported in patients receiving therapy with Pirfemac. Rarely these have been associated with concomitant elevations in total serum bilirubin. Liver function tests (ALT, AST and bilirubin) should be conducted prior to the initiation of treatment with Pirfemac, and subsequently at monthly intervals for the first 6 months and then every 3 months thereafter. In the event of significant elevation of liver aminotransferases the dose of Pirfemac should be adjusted or treatment discontinued according to the guidelines listed below. For patients with confirmed elevations in ALT, AST or bilirubin during treatment, the following dose adjustments may be necessary.

Recommendations in case of ALT/AST elevations: If a patient exhibits an aminotransferase elevation to >3 to £5 x ULN after starting Pirfemac therapy, confounding medicinal products should be discontinued, other causes excluded, and the patient monitored closely. If clinically appropriate the dose of Pirfemac should be reduced or interrupted. Once liver function tests are within normal limits Pirfemac may be re-escalated to the recommended daily dose if tolerated.

If a patient exhibits an aminotransferase elevation to £5 x ULN accompanied by symptoms or hyperbilirubinaemia, Pirfemac should be discontinued and the patient should not be rechallenged.

If a patient exhibits an aminotransferase elevation to >5 x ULN, Pirfemac should be discontinued and the patient should not be rechallenged.

Hepatic impairment: In subjects with moderate hepatic impairment (i.e. Child-Pugh Class B), Pirfemac exposure was increased by 60%. Pirfemac should be used with caution in patients with pre-existing mild to moderate hepatic impairment (i.e. Child-Pugh Class A and B) given the potential for increased Pirfemac exposure. Patients should be monitored closely for signs of toxicity especially if they are concomitantly taking a known CYP1A2 inhibitor. Pirfemac has not been studied in individuals with severe hepatic impairment and Pirfemac should not be used in patients with severe hepatic impairment.

Photosensitivity reaction and rash: Exposure to direct sunlight (including sunlamps) should be avoided or minimised during treatment with Pirfemac. Patients should be instructed to use a sunblock daily, to wear clothing that protects against sun exposure, and to avoid other medicinal products known to cause photosensitivity. Patients should be instructed to report symptoms of photosensitivity reaction or rash to their physician. Severe photosensitivity reactions are uncommon. Dose adjustments or temporary treatment discontinuation may be necessary in mild to severe cases of photosensitivity reaction or rash.

Dizziness: Dizziness has been reported in patients taking Pirfemac. Therefore, patients should know how they react to this medicinal product before they engage in activities requiring mental alertness or coordination. In clinical studies, most patients who experienced dizziness had a single event, and most events resolved, with a median duration of 22 days. If dizziness does not improve or if it worsens in severity, dose adjustment or even discontinuation of Pirfemac may be warranted.

Fatigue: Fatigue has been reported in patients taking Pirfemac. Therefore, patients should know how they react to this medicinal product before they engage in activities requiring mental alertness or coordination.

Weight loss: Weight loss has been reported in patients treated with Pirfemac. Physicians should monitor patients’ weight, and when appropriate encourage increased caloric intake if weight loss is considered to be of clinical significance.

Interactions with other medicinal products and other forms of interaction

Approximately 70-80% of pirfenidone is metabolised via CYP1A2 with minor contributions from other CYP isoenzymes including CYP2C9, 2C19, 2D6 and 2E1.

Consumption of grapefruit juice is associated with inhibition of CYP1A2 and should be avoided during treatment with pirfenidone.

Fluvoxamine and inhibitors of CYP1A2: In a Phase 1 study, the co-administration of Pirfemac and fluvoxamine (a strong inhibitor of CYP1A2 with inhibitory effects on other CYP isoenzymes [CYP2C9, 2C19, and 2D6]) resulted in a 4-fold increase in exposure to pirfenidone in non-smokers.

Pirfemac is contraindicated in patients with concomitant use of fluvoxamine. Fluvoxamine should be discontinued prior to the initiation of Pirfemac therapy and avoided during Pirfemac therapy due to the reduced clearance of pirfenidone. Other therapies that are inhibitors of both CYP1A2 and one or more other CYP isoenzymes involved in the metabolism of pirfenidone (e.g. CYP2C9, 2C19, and 2D6) should be avoided during pirfenidone treatment.

In vitro in vivo extrapolations indicate that strong and selective inhibitors of CYP1A2 (e.g. enoxacin) have the potential to increase the exposure to pirfenidone by approximately 2 to 4-fold. If concomitant use of Pirfemac with a strong and selective inhibitor of CYP1A2 cannot be avoided, the dose of Pirfemac should be reduced to 801 mg daily (one capsule, three times a day). Patients should be closely monitored for emergence of adverse reactions associated with Pirfemac therapy. Discontinue Pirfemac if necessary.

Co-administration of Pirfemac and 750 mg of ciprofloxacin (a moderate inhibitor of CYP1A2) increased the exposure to pirfenidone by 81%. If ciprofloxacin at the dose of 750 mg twice daily cannot be avoided, the dose of Pirfemac should be reduced to 1602 mg daily (two capsules, three times a day). Pirfemac should be used with caution when ciprofloxacin is used at a dose of 250 mg or 500 mg once or twice daily.

Pirfemac should be used with caution in patients treated with other moderate inhibitors of CYP1A2 (e.g. amiodarone, propafenone).

Special care should also be exercised if CYP1A2 inhibitors are being used concomitantly with potent inhibitors of one or more other CYP isoenzymes involved in the metabolism of pirfenidone such as CYP2C9 (e.g. amiodarone, fluconazole), 2C19 (e.g. chloramphenicol) and 2D6 (e.g. fluoxetine, paroxetine).

Cigarette smoking and inducers of CYP1A2: A Phase 1 interaction study evaluated the effect of cigarette smoking (CYP1A2 inducer) on the pharmacokinetics of Pirfemac. The exposure to pirfenidone in smokers was 50% of that observed in non-smokers. Smoking has the potential to induce hepatic enzyme production and thus increase medicinal product clearance and decrease exposure. Concomitant use of strong inducers of CYP1A2 including smoking should be avoided during Pirfemac therapy based on the observed relationship between cigarette smoking and its potential to induce CYP1A2. Patients should be encouraged to discontinue use of strong inducers of CYP1A2 and to stop smoking before and during treatment with pirfenidone.

In the case of moderate inducers of CYP1A2 (e.g. omeprazole), concomitant use may theoretically result in a lowering of pirfenidone plasma levels.

Co-administration of medicinal products that act as potent inducers of both CYP1A2 and the other CYP isoenzymes involved in the metabolism of pirfenidone (e.g. rifampicin) may result in significant lowering of pirfenidone plasma levels. These medicinal products should be avoided whenever possible.

Acute Overdose

There is limited clinical experience with overdose. Multiple doses of pirfenidone up to a dose of 4806 mg/day were administered as six 267 mg capsules three times daily to healthy adult volunteers over a 12-day dose escalation period. Adverse reactions were mild, transient, and consistent with the most frequently reported adverse reactions for pirfenidone.

Storage Condition

Store in a cool and dry place, protected from light.

Innovators Monograph

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