Pirfenidone

Indications

Pirfenidone is used for: Idiopathic pulmonary fibrosis (IPF)

Adult Dose

Idiopathic Pulmonary Fibrosis Initial dose titration Days 1-7: 267 mg (1 capsule) PO TID Days 8-14: 534 mg (2 capsules) PO TID Day 15 and thereafter: 801 mg (3 capsules) PO TID Maintenance dose 801 mg (3 capsules) PO TID with food Not to exceed 2403 mg/day (9 capsules/day) Hepatic impairment Mild-to-moderate (Child Pugh A or B): Use caution; monitor and consider dosage modification or discontinuation as needed Severe (Child Pugh C): Not recommended (not studied)

Child Dose

Safety and efficacy not established

Renal Dose

Renal impairment Mild, moderate, or severe: Use caution; monitor and consider dosage modification or discontinuation as needed ESRD requiring dialysis: No recommended (not studied)

Administration

Should be taken with food: Take w/ food to reduce the possibility of nausea & dizziness. Swallow whole w/ water. Take doses at same time each day.

Contra Indications

Hypersensitivity. History of angioedema. Severe hepatic & renal impairment or end stage liver & renal disease. Concomitant use w/ fluvoxamine.

Precautions

Hepatic function abnormalities, hepatic impairment, photosensitivity reaction or rash, angioedema, dizziness, fatigue & wt loss. May affect ability to drive or operate machinery. Avoid use in pregnancy & lactation.

Pregnancy-Lactation

Pregnancy: Data in pregnant women are insufficient to inform on drug associated risks for major birth defects and miscarriage Lactation: No information is available on presence of pirfenidone in human milk, effects of drug on breastfed infant, or effects of drug on milk production; lack of clinical data during lactation precludes clear determination of risk of pirfenidone to infant during lactation; developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and potential adverse effects on breastfed child from pirfenidone or from underlying maternal condition

Interactions

Inhibition of CYP1A2 w/ concomitant grapefruit juice. Increased exposure w/ fluvoxamine & other strong & selective CYP1A2 inhibitors, ciprofloxacin, amiodarone, propafenone. Potential to induce hepatic enzyme production by smoking. Lowered plasma levels w/ omeprazole, rifampicin.

Adverse Effects

Side effects of Pirfenidone : >10% Nausea (36%), Rash (30%), Upper respiratory tract infection (27%), Diarrhea (26%), Abdominal pain (24%), Headache (22%), Dyspepsia (19%), Dizziness (18%), Vomiting (13%), GERD (11%), Sinusitis (11%) 1-10% Insomnia (10%), Weight decreased (10%), Arthralgia (10%), Photosensitivity (9%), Decreased appetite (8%), Pruritus (8%), Asthenia (6%), Dysgeusia (6%), Noncardiac chest pain (5%), AST/ALT ≥3 x ULN (3.7%) <1% AST/ALT ≥10 x ULN (0.3%)

Mechanism of Action

Precise mechanism by which pirfenidone may work in pulmonary fibrosis has not been established Inhibits transforming growth factor (TGF)-beta, a chemical mediator that controls many cell functions including proliferation and differentiation Also inhibits the synthesis of TNF-alpha, a cytokine that is known to have an active role in inflammation