All about Perfecine (Pirfenidone) tablet

Name of Medicine: Perfecine

Composition: Pirfenidone

Chemical Formula: C12H11NO 

Description: Perfecine is a pirfenidone formulation proven to be an effective clinical solution for the treatment of Idiopathic Pulmonary Fibrosis. 

Perfecine is a clinically effective regimen comprising Pirfenidone and some inactive ingredients namely talc, microcrystalline cellulose, povidone, croscarmellose sodium, magnesium stearate, colloidal anhydrous silica, polyvinyl alcohol, iron oxide, titanium dioxide, and macrogol (polyethylene glycol). 

Clinical Relevance

Perfecine (Pirfenidone) is an established drug indicated for use in patients suffering from Idiopathic Pulmonary Fibrosis, a rare and progressive disease of the respiratory system that is highly associated and related to the formation of scar tissue. This scar tissue is thought to thicken over a period of hindering lung function. It is important to know that Perfecine (Pirfenidone) is not the cure for IPF, however, it is efficacious enough to slow the progress of the disease and increase the survival period of the patients. 

Clinical Pharmacology 

Mechanism of Action

Although the accurate mechanism of action of pirfenidone and its related molecular targets have yet to be investigated, the regimen has shown anti-fibrotic, anti-inflammatory, and antioxidant effects. One vital anti-fibrotic procedure includes suppression of TGF-β1 (transforming growth factor-β1), a key cytokine involved in fibrogenesis and extracellular matrix production. There is also evidence to prove that this compound possesses the ability to downregulate the expression of potent pro-inflammatory cytokines like TNF-α, interleukin-1, and interferon-gamma. In animal models, it can successfully inhibit both the influx of inflammatory cells and the increased pulmonary vascular permeability that is induced by bleomycin.

Pharmacodynamics 

Pirfenidone is one of the novel agents possessing anti-inflammatory, antioxidant, and antifibrotic properties. It may tend to improve lung function and decrease the total number of acute exacerbations in patients suffering from idiopathic pulmonary fibrosis (IPF).

Pharmacokinetics

• Absorption: Rapidly absorbed following oral administration.

• The volume of Distribution: The steady-state volume of distribution after oral administration of the regimen is nearly 70L

• Protein Binding: It is 50-58% protein-bound in plasma, primarily to albumin.

• Half-Life: 2-2.5 hours

• Toxicity: Generally well tolerated with the most common adverse effects reported being photosensitivity rash and gastrointestinal signs.

Clinical Trials

In two of three phases 3 trials, Perfecine (Pirfenidone), an oral antifibrotic therapy, tend to reduce disease progression, as investigated by the decline in forced vital capacity (FVC) or vital capacity, in patients suffering from idiopathic pulmonary fibrosis. The ultimate analysis of all-cause mortality demonstrated a decrease in the number of deaths in the pirfenidone group as compared to the placebo group, although the difference was not vital. Eleven patients (4.0%) in this group died during the study, as compared with 20 patients (7.2%) in the placebo group (hazard ratio, 0.55; 95% CI, 0.26 to 1.15; P=0.10). Deaths from idiopathic pulmonary fibrosis occurred in 3 subjects (1.1%) and 7 patients (2.5%) in the pirfenidone and placebo groups, respectively (hazard ratio, 0.44; 95% CI, 0.11 to 1.72; P=0.23). In the prespecified analysis of all-cause mortality in the pooled population of 1247 patients (555 from the ASCEND study and 692 from the CAPACITY studies), the regimen showed a reduction in the risk of death at 1 year by 48%, as compared with placebo. In addition, in the pooled population, the risk of death from idiopathic pulmonary fibrosis at 1 year was also decreased by 68% in the pirfenidone group, as compared with the placebo group (hazard ratio, 0.32; 95% CI, 0.14 to 0.76; P=0.006).

Drug Interactions 

CYP1A2 Inhibitors

• Strong CYP1A2 Inhibitors: The concomitant administration of Perfecine and any strong CYP1A2 inhibitor like fluvoxamine is not recommended because the drug can significantly increase the exposure to Pirfenidone. This is why the use of a strong CYP1A2 inhibitor should be discontinued before and during the treatment with Perfecine. If the administration can not be avoided, certain dose reductions need to be initiated. 

• Moderate CYP1A2 Inhibitors: The concomitant administration of Perfecine and any moderate inhibitor of CYP1A2 like ciprofloxacin is not recommended because the drug can significantly increase the exposure to Pirfenidone. This is why the use of a moderate CYP1A2 inhibitor should be discontinued before and during the treatment with Perfecine. If the administration can not be avoided, certain dose reductions need to be initiated.

• Concomitant CYP1A2 and other CYP Inhibitors: The agents that are thought to be moderate or strong inhibitors of CYP1A2 and any other CYP isoenzymes that are involved in the metabolism of Perfecine like CYP2C9, 2C19, 2D6, and 2E1 should be primarily discontinued before starting the administration of Perfecine. 

CYP1A2 Inducers

• The concomitant administration of Perfecine and a CYP1A2 inducer may lead to a significant decrease in the exposure to Pirfenidone leading to loss of drug efficacy. This is why the use of a CYP1A2 inducer should be discontinued before and during the treatment with Perfecine.

Drug Category

• Antirheumatic Agents: These are the drugs that are used in inflammatory arthritis including ankylosing spondylitis, rheumatoid arthritis, idiopathic juvenile arthritis, and psoriatic arthritis. Antirheumatic Agents work by suppressing the activity of overactive immune or inflammatory systems in the body. 

• Immunosuppressive Agents: These agents are used to treat autoimmune diseases. Immunosuppressive Agents work by weakening the action of the immune system to decrease the impact of autoimmune disorders on the body. 

• Analgesics: These are the drugs that are used to get relief from pain. Such regimens are also referred to as pain killers or pain relievers. Analgesics provide relief without making the person lose consciousness or sleep, in general. 

• Antineoplastic Agents: These are the special anti-cancer agents used in the treatment of certain types of cancers. Antineoplastic Agents are also referred to as cytotoxic or hazardous drugs. These medications work by rapidly killing the cancerous cells in the body. 

Dosage and Administration

Recommended Dose 

Before initiating the treatment with Perfecine (Pirfenidone), liver function tests should be done and investigated by the healthcare team. The recommended daily maintenance dosage of Perfecine is 800 mg three times a day. Further, dose increase or decrease shall be done as per the medical condition and requirements of the patient. 

Dose Modifications

• Due to drug interactions: Several dose modifications may be needed if the patient is administering any of the mentioned drugs with Perfecine (Pirfenidone): moderate or strong CYP1A2 Inhibitor, concomitant CYP1A2, and other CYP Inhibitor, and CYP1A2 Inducer. 

• Due to adverse reactions: In patients who experience serious reactions including gastrointestinal disorders, liver dysfunction, or photosensitivity, or severe rash, several dose modifications may be needed. 

Overdosage 

There is very limited data available showing the cases of overdosage and related adverse events. However, in the event of a suspected overdose, the patient should be hospitalized and be monitored for vital signs and symptoms. The clinical status of the patient should be observed till necessary. 

Adverse Reactions

Administration of Perfecine (Pirfenidone) in patients may sometimes lead to certain adverse reactions. Such reactions should be informed to the patients before starting the therapy. It is important to monitor the patients for adverse reactions and initiate dose adjustments or modifications if needed. 

Certain Gastrointestinal Disorders may occur during the course of Perfecine (Pirfenidone) including incontinence (involuntary leakage of urine), nausea, vomiting, abdominal pain (pain in the belly), heartburn, diarrhea, dyspepsia (indigestion), and constipation.

Allergic reactions or photosensitivity effects may be also experienced by some patients such as skin rash, itching, swelling on the face, tongue, legs, or throat, redness on the skin, photosensitivity, and blurred vision. 

Some patients may also experience certain effects of the Central Nervous System namely severe headache, dizziness, and drowsiness. In most cases, these reactions are accompanied by fever and chills. 

Other common adverse reactions associated with the administration of Perfecine (Pirfenidone) are weight loss or gain, sore throat, stuffy nose, joint pain, bone pain, insomnia (difficulty in sleeping), loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes), and difficulty in breathing. 

Warnings and Precautions 

General Warnings

Elevated Liver Enzymes 

Administration of Perfecine can lead to an increase in liver enzymes in the patients. As per the clinical trials, no cases of a liver transplant due to liver failure were reported. However, it is important to conduct liver function tests prior to the first dose of Perfecine, then once a month during the therapy to avoid any complications. 

Photosensitivity Reaction or Rash 

Administration of Perfecine can lead to an increased risk of photosensitivity reactions or skin rash. As per the clinical trials, administration of Perfecine showed a greater incidence of such adverse events in patients. Such reactions can occur majorly in the first 6 months of the therapy. It is important to instruct the patients to minimize exposure to sunlight. Also, instruct the patients to avoid using drugs that are known to cause the same reaction. 

Gastrointestinal Disorders

Administration of Perfecine can lead to gastrointestinal disorders including nausea, vomiting, gastroesophageal reflux disease, and stomach pain more frequently in the patients. As per the clinical trials, the incidence of such adverse effects was highest and it also showed a decrease over time. However, dose modifications may be necessary in some severe cases. 

Special Population

Pregnancy

Administration of Perfecine in pregnant women might lead to birth defects and miscarriage. However, there is very insufficient data available to showcase the drug-related adverse effects on women who are pregnant. To take necessary precautions, you may be recommended to not initiate the use of Perfecine during pregnancy. 

Lactation

Administration of Perfecine in lactating women might lead to severe effects on the child. However, there is very insufficient data available to showcase the presence or excretion of the drug into human milk in any form. To take necessary precautions, you may be recommended to not initiate the use of Perfecine during breastfeeding. The patients may also be asked to discontinue breastfeeding if the administration of Perfecine is unavoidable. 

Pediatrics and Geriatrics

The safety and efficacy of Perfecine have not yet been established in pediatric patients. However, in the case of geriatric patients, no overall safety and efficacy difference was noted in the trials. Similarly, no dose adjustments may be needed initially. 

Hepatic Impairment

Administration of Perfecine should be done with extreme caution in patients suffering from mild to moderate (Child-Pugh Class A-B) hepatic impairment. It is important to monitor such patients for adverse reactions. Perfecine is not indicated for use in patients suffering from severe hepatic impairment since the safety, efficacy, and pharmacokinetics have not yet been studied in such patients. 

Renal Impairment

Administration of Perfecine should be done with extreme caution in patients suffering from mild, moderate, or severe renal impairment. It is important to monitor such patients for adverse reactions. Perfecine is not indicated for use in patients suffering from an end-stage renal disease that requires dialysis since the safety, efficacy, and pharmacokinetics have not yet been studied in such patients. 

Smokers

Smoking can lead to a decrease in exposure to Perfecine. This can alter the efficacy of the drug. It is important to instruct the patients to stop smoking prior to and during the therapy. 

Packaging and Storage

Perfecine tablets contain 200mg Pirfenidone. The tablets are indicated for oral administration only in a fixed strength as per the doctor’s prescription. Store Perfecine tablets at 59°F to 86°F (15°C to 30°C). Keep this regimen away from the reach of especially pets and children. Do not place the medication under direct exposure to light or heat. Protect Perfecine tablets from moisture. Learn the ways to dispose of the used and expired packs of Perfecine from your nearest pharmacist. Especially women who are pregnant should avoid handling Perfecine tablets without protection (gloves).