Drug Class Description

Generic Name

Drug Description

Presentation

Indications

Malarone is a fixed dose combination of atovaquone and proguanil hydrochloride which acts as a blood schizonticide and also has activity against hepatic schizonts of Plasmodium falciparum. It is indicated for:

Prophylaxis of Plasmodium falciparum malaria.

Treatment of acute, uncomplicated Plasmodium falciparum malaria.

Because Malarone is effective against drug sensitive and drug resistant P. falciparum it is especially recommended for prophylaxis and treatment of P. falciparum malaria where the pathogen may be resistant to other antimalarials.

Official guidelines and local information on the prevalence of resistance to antimalarial drugs should be taken into consideration. Official guidelines will normally include WHO and public health authorities' guidelines.

Adult Dosage

Prophylaxis:

Prophylaxis should

• commence 24 or 48 hours prior to entering a malaria-endemic area,

• continue during the period of the stay, which should not exceed 28 days,

• continue for 7 days after leaving the area.

In residents (semi-immune subjects) of endemic areas, the safety and effectiveness of Malarone has been established in studies of up to 12 weeks.

Dosage in Adults

One Malarone tablet daily.

Malarone tablets are not recommended for malaria prophylaxis in persons under 40 kg bodyweight.

Treatment

Dosage in Adults

Four Malarone tablets as a single dose for three consecutive days.

Dosage in Hepatic Impairment

A pharmacokinetic study indicates that no dosage adjustments are needed in patients with mild to moderate hepatic impairment. Although no studies have been conducted in patients with severe hepatic impairment, no special precautions or dosage adjustment are anticipated.

Dosage in Renal Impairment

Pharmacokinetic studies indicate that no dosage adjustments are needed in patients with mild to moderate renal impairment. In patients with severe renal impairment (creatine clearance <30 mL/min) alternatives to Malarone for treatment of acute P. falciparum malaria should be recommended whenever possible. For prophylaxis of P. falciparum malaria in patients with several renal impairments Contraindications.

Child Dosage

Elderly Dosage

A pharmacokinetic study indicates that no dosage adjustments are needed in the elderly.

Contra Indications

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

Malarone is contraindicated for prophylaxis of P. falciparum malaria in patients with severe renal impairment (creatine clearance <30 mL/min).

Special Precautions

Persons taking Malarone for prophylaxis or treatment of malaria should take a repeat dose if they vomit within 1 hour of dosing. In the event of diarrhoea, normal dosing should be continued. Absorption of atovaquone may be reduced in patients with diarrhoea or vomiting, but diarrhoea or vomiting was not associated with reduced efficacy in clinical trials of Malarone for malaria prophylaxis. However, as with other antimalarial agents, subjects with diarrhoea or vomiting should be advised to continue with malaria prevention measures by complying with personal protection measures (repellants, bednets).

In patients with acute malaria who present with diarrhoea or vomiting, alternative therapy should be considered. If Malarone is used to treat malaria in these patients, parasitaemia and the patient's clinical condition should be closely monitored.

Malarone has not been evaluated for the treatment of cerebral malaria or other severe manifestations of complicated malaria including hyperparasitaemia, pulmonary oedema or renal failure.

Occasionally, severe allergic reactions (including anaphylaxis) have been reported in patients taking Malarone. If patients experience an allergic reaction Malarone should be discontinued promptly and appropriate treatment initiated.

Malarone has been shown to have no efficacy against hypnozoites of Plasmodium vivax as parasite relapse occurred commonly when P. vivax malaria was treated with Malarone alone. Travellers with intense exposure to P. vivax or P. ovale, and those who develop malaria caused by either of these parasites, will require additional treatment with a drug that is active against hypnozoites.

In the event of recrudescent infections due to P. falciparum after treatment with Malarone, or failure of chemoprophylaxis with Malarone, patients should be treated with a different blood schizonticide as such events can reflect a resistance of the parasite.

Parasitaemia should be closely monitored in patients receiving concurrent tetracycline.

The concomitant administration of Malarone and efavirenz or boosted protease-inhibitors should be avoided whenever possible. The concomitant administration of Malarone and rifampicin or rifabutin is not recommended.

Concurrent use of metoclopramide is not recommended. Another antiemetic treatment should be given.

Caution is advised when initiating or withdrawing malaria prophylaxis or treatment with Malarone in patients on continuous treatment with warfarin and other coumarin based anticoagulants.

Atovaquone can increase the levels of etoposide and its metabolite. In patients with severe renal impairment (creatinine clearance <30 mL/min) alternatives to Malarone for treatment of acute P. falciparum malaria should be recommended whenever possible.

The safety and effectiveness of Malarone (atovaquone 250mg/proguanil hydrochloride 100mg tablets) has not been established for prophylaxis of malaria in patients who weigh less than 40kg, or in the treatment of malaria in paediatric patients who weigh less than 11kg.

Interactions

Concomitant administration of rifampicin or rifabutin is not recommended as it is known to reduce plasma concentrations of atovaquone levels by approximately 50% and 34%, respectively.

Concomitant treatment with metoclopramide has been associated with a significant decrease (about 50 %) in plasma concentrations of atovaquone. Another antiemetic treatment should be given.

When given with efavirenz or boosted protease-inhibitors, atovaquone concentrations have been observed to decrease as much as 75%. This combination should be avoided whenever possible

Proguanil may potentiate the effect of warfarin and other coumarin based anticoagulants which may lead to an increase in the risk of haemorrhage. The mechanism of this potential drug interaction has not been established. Caution is advised when initiating or withdrawing malaria prophylaxis or treatment with atovaquone-proguanil in patients on continuous treatment with oral anticoagulants. The dose of the oral anticoagulant may need to be adjusted during Malarone treatment or after its withdrawal, based on INR results.

Concomitant treatment with tetracycline has been associated with decreases in plasma concentrations of atovaquone.

The co-administration of atovaquone at doses of 45mg/kg/day in children (n=9) with acute lymphoblastic leukaemia for prophylaxis of PCP was found to increase the plasma concentrations (AUC) of etoposide and its metabolite etoposide catechol by a median of 8.6% (P=0.055) and 28.4% (P=0.031) (respectively compared to the co-administration of etoposide and sulfamethoxazole-trimethoprim). Caution should be advised in patients receiving concomitant therapy with etoposide.

Proguanil is primarily metabolised by CYP2C19. However, potential pharmacokinetic interactions with other substrates, inhibitors (e.g. moclobemide, fluvoxamine) or inducers (e.g. artemisinin, carbamazepine) of CYP2C19 are unknown.

Adverse Reactions

In clinical trials of Malarone in the treatment of malaria the most commonly reported adverse reactions were abdominal pain, headache, anorexia, nausea, vomiting, diarrhoea and coughing. In clinical trials of Malarone for prophylaxis of malaria, the most commonly reported adverse reactions were headache, abdominal pain and diarrhoea.

The following table provides a summary of adverse reactions that have been reported to have a suspected (at least possible) causal relationship to treatment with atovaquone-proguanil in clinical trials and spontaneous post-marketing reports. The following convention is used for the classification of frequency: very common (1/10); common (1/100 to <1/10); uncommon (1/1,000 to <1/100); not known (cannot be estimated from the available data).

There are limited long term safety data in children. In particular, the long-term effects of Malarone on growth, puberty and general development have not been studied.

1. Frequency taken from atovaquone label. Patients participating in clinical trials with atovaquone have received higher doses and have often had complications of advance Human Immunodeficiency Virus (HIV) disease. These events may have been seen at a lower frequency or not at all in clinical trials with atovaquone-proguanil.

2. Observed from post-marketing spontaneous reports and the frequency is therefore unknown

3. Observed with proguanil.

Manufacturer

Drug Availability

Updated