Erlonat (Erlotinib)

Definition:

Erlotinib, generic for the trade name of Erlonat

Erlonat is the prescription medicine; it is prescribed for the patient only under the guidance of medical oncologist

Erlonat is comes under the class of “Tyrosine kinase inhibitor”

Tyrosine kinase is the one type of protein, which is essential for the cell growth

Erlonat involves in blockade of signals within the cancer cells

When Erlotinib (Erlonat) used

Erlonat is mainly used in the treatment of;

Advanced or metastatic non-small cell lung cancer

Main key points:

Erlonat is involved as first line treatment

Erlonat is also considered as maintenance therapy, patient those who are withstand after four chemotherapy cycles

Erlonat is used in the therapy for the patients whose cancer relapses after chemotherapy

Erlonat (Erlotinib) is also indicated for the treatment of advanced pancreatic cancer, by concomitant with Gemcitabine.

Erlonat mechanism;

Erlotinib, it works by exhibiting tyrosine kinase inhibitor activity.

Epidermal growth factor receptor (EGFR) is present on the surface of the cancer cells and in normal cells.

Cancer cells transmits signals through these receptors, which is essential for cell survival

Erlotinib prohibits kinase activity of EGFR and preventing the autophosphorylation of kinase residues related to receptor.

This inhibition of signal transduction causes cell death

ADME properties

Absorption:

The absorption of drug Erlotinib occurs after oral administration with the range of 60%

The bioavailability of drug is increased while taking with food to 100%

The peak plasma concentration of Erlotinib occur 4 hours after dosing

Distribution:

The apparent volume of distribution occurs at 232L

Nearly 98% of drug highly bound to the human plasma protein like albumin and alpha 1 acid glycoprotein

Metabolism:

Mostly the metabolism of the drug occurs in the liver. Metabolism undergone by using various cytochrome isoenzymes CYP3A4

Elimination:

About 91% of drug eliminated through feces and remaining will be excreted through urine

The median half-life period of the Erlotinib is occurs around 36.2 hours

Dosage and administration:

Non-small cell lung cancer:

The recommended dose of Erlonat is 150mg PO qDay 1 hr before or 2 hours after meals

Erlonat should be administered on an empty stomach

Limitations:

Erlonat not used in combination with platinum-based compounds

Safety and efficacy has not been established

Pancreatic cancer:

The prescribed dose is 150mg PO qDay with gemcitabine

Ant acids should not concomitant with Erlonat

 Take Erlonat 10 hours after or 2 hours before administration of antacids

In pediatrics:

The safety and efficacy of the drug Erlotinib has not been established

Tablet Erlonat causes side effeects

>10%

Rashes, anorexia, diarrhea, fatigue, nausea, infection, vomiting, dyspnea, stomatitis, cough, Pruritus, conjunctivitis, dry skin, keratoconjunctivitis sicca, abdominal pain

1-10%

Elevation of LFT

Acne, paronychia,

 Weight loss,

Pneumonitis pulmonary infiltrate,

Pulmonary fibrosis

<1%

Interstitial lung disease

Post marketing reports:

Musculoskeletal and connective tissue disorders: myopathy, rhabdomyolysis

Eye: ocular inflammation including uveitis

 Erlonat interacts with

Co administration of Erlonat with strong CYP3A4 inhibitors or combined with CYP3A4 & CYP1A2 leads to increase Erlotinib exposure

CYP3A4 inhibitors like; boceprevir, clarithromycin, conivaptan, indinavir, itraconazole, ketoconazole, posaconazole, ritonavir, grapefruit 

CYP3A4 & CYP1A2 inhibitors: ciprofloxacin

Cigarette smoking will decrease the Erlotinib exposure

While combining with coumarin derived anti-coagulants monitors the bleeding reactions and prothrombin time because it may cause elevation of bleeding

Precaution

If taking Erlonat, caution should be taken in the condition of;

Interstitial lung disease

Renal failure

 Hepatotoxicity

Gastrointestinal perforation

Bullous and exfoliative skin disorders

Cerebrovascular accident

Ocular disorders

Hemorrhage

Embryo fetal toxicity

Contraindicated to

Pregnancy and women who become pregnant

Breast feeding

Hypersensitivity reaction

Pregnancy and lactation:

Pregnancy category: D

Erlonat should not be used in pregnancy period and lactation

Storage and handling:

The storage of Erlonat tablets container should be kept at 25^oC (77^oF); excursion between 15^oC to 30^oC

Container should be kept away from moisture, heat and light

Missed dose:

In case of missed dose, the patient should be advice by taking missed tablet within the period of next dose; otherwise the dose will be skipped and follow the regular dosing schedule

Do not double the dose