Atovaquone and Proguanil Hydrochloride

1 INDICATIONS AND USAGE Atovaquone and proguanil hydrochloride tablets are an antimalarial indicated for: prophylaxis of Plasmodium falciparum malaria, including in areas where chloroquine resistance has been reported. ( 1.1 ) treatment of acute, uncomplicated P. falciparum malaria. ( 1.2 ) 1.1 Prevention of Malaria Atovaquone and proguanil hydrochloride tablets are indicated for the prophylaxis of Plasmodium falciparum malaria, including in areas where chloroquine resistance has been reported. 1.2 Treatment of Malaria Atovaquone and proguanil hydrochloride tablets are indicated for the treatment of acute, uncomplicated P. falciparum malaria. Atovaquone and proguanil hydrochloride tablets have been shown to be effective in regions where the drugs chloroquine, halofantrine, mefloquine, and amodiaquine may have unacceptable failure rates, presumably due to drug resistance.

2 DOSAGE AND ADMINISTRATION The daily dose should be taken at the same time each day with food or a milky drink. In the event of vomiting within 1 hour after dosing, a repeat dose should be taken. Atovaquone and proguanil hydrochloride tablets may be crushed and mixed with condensed milk just prior to administration to patients who may have difficulty swallowing tablets. Atovaquone and proguanil hydrochloride tablets should be taken with food or a milky drink. Prophylaxis ( 2.1 ) : Start prophylaxis 1 or 2 days before entering a malaria-endemic area and continue daily during the stay and for 7 days after return. Adults: One adult strength tablet per day. Pediatric Patients: Dosage based on body weight (see Table 1). Treatment ( 2.2 ) : Adults: Four adult strength tablets as a single daily dose for 3 days. Pediatric Patients: Dosage based on body weight (see Table 2). Renal Impairment ( 2.3 ) : Do not use for prophylaxis of malaria in patients with severe renal impairment. Use with caution for treatment of malaria in patients with severe renal impairment. 2.1 Prevention of Malaria Start prophylactic treatment with atovaquone and proguanil hydrochloride tablets 1 or 2 days before entering a malaria-endemic area and continue daily during the stay and for 7 days after return. Adults One atovaquone and proguanil hydrochloride tablet (adult strength = 250 mg atovaquone/100 mg proguanil hydrochloride) per day. Pediatric Patients The dosage for prevention of malaria in pediatric patients is based upon body weight (Table 1). Table 1. Dosage for Prevention of Malaria in Pediatric Patients Weight (kg) Atovaquone/ Proguanil HCl Total Daily Dose Dosage Regimen 11-20 62.5 mg/25 mg 1 atovaquone and proguanil hydrochloride pediatric tablet daily 21-30 125 mg/50 mg 2 atovaquone and proguanil hydrochloride pediatric tablets as a single daily dose 31-40 187.5 mg/75 mg 3 atovaquone and proguanil hydrochloride pediatric tablets as a single daily dose > 40 250 mg/100 mg 1 atovaquone and proguanil hydrochloride tablet (adult strength) as a single daily dose 2.2 Treatment of Acute Malaria Adults Four atovaquone and proguanil hydrochloride tablets (adult strength; total daily dose 1 g atovaquone/400 mg proguanil hydrochloride) as a single daily dose for 3 consecutive days. Pediatric Patients The dosage for treatment of acute malaria in pediatric patients is based upon body weight (Table 2). Table 2. Dosage for Treatment of Acute Malaria in Pediatric Patients Weight (kg) Atovaquone/ Proguanil HCl Total Daily Dose Dosage Regimen 5-8 125 mg/50 mg 2 atovaquone and proguanil hydrochloride pediatric tablets daily for 3 consecutive days 9-10 187.5 mg/75 mg 3 atovaquone and proguanil hydrochloride pediatric tablets daily for 3 consecutive days 11-20 250 mg/100 mg 1 atovaquone and proguanil hydrochloride tablet (adult strength) daily for 3 consecutive days 21-30 500 mg/200 mg 2 atovaquone and proguanil hydrochloride tablets (adult strength) as a single daily dose for 3 consecutive days 31-40 750 mg/300 mg 3 atovaquone and proguanil hydrochloride tablets (adult strength) as a single daily dose for 3 consecutive days > 40 1 g/400 mg 4 atovaquone and proguanil hydrochloride tablets (adult strength) as a single daily dose for 3 consecutive days 2.3 Renal Impairment Do not use atovaquone and proguanil hydrochloride tablets for malaria prophylaxis in patients with severe renal impairment (creatinine clearance < 30 mL/min) [see Contraindications (4) ] . Use with caution for the treatment of malaria in patients with severe renal impairment, only if the benefits of the 3-day treatment regimen outweigh the potential risks associated with increased drug exposure. No dosage adjustments are needed in patients with mild (creatinine clearance 50 to 80 mL/min) or moderate (creatinine clearance 30 to 50 mL/min) renal impairment. [See Clinical Pharmacology (12.3) .]

4 CONTRAINDICATIONS Atovaquone and proguanil hydrochloride tablets are contraindicated in individuals with known hypersensitivity reactions (e.g., anaphylaxis, erythema multiforme or Stevens-Johnson syndrome, angioedema, vasculitis) to atovaquone or proguanil hydrochloride or any component of the formulation. Atovaquone and proguanil hydrochloride tablets are contraindicated for prophylaxis of P. falciparum malaria in patients with severe renal impairment (creatinine clearance < 30 mL/min) because of pancytopenia in patients with severe renal impairment treated with proguanil [see Use in Specific Populations (8.6) , Clinical Pharmacology (12.3) ] . Known serious hypersensitivity reactions to atovaquone or proguanil hydrochloride or any component of the formulation. ( 4 ) Prophylaxis of P. falciparum malaria in patients with severe renal impairment (creatinine clearance < 30 mL/min). ( 4 )

5 WARNINGS AND PRECAUTIONS Atovaquone absorption may be reduced in patients with diarrhea or vomiting. If used in patients who are vomiting, parasitemia should be closely monitored and the use of an antiemetic considered. In patients with severe or persistent diarrhea or vomiting, alternative antimalarial therapy may be required. ( 5.1 ) In mixed P. falciparum and Plasmodium vivax infection, P. vivax relapse occurred commonly when patients were treated with atovaquone and proguanil hydrochloride tablets alone. ( 5.2 ) In the event of recrudescent P. falciparum infections after treatment or prophylaxis failure, patients should be treated with a different blood schizonticide. ( 5.2 ) Elevated liver laboratory tests and cases of hepatitis and hepatic failure requiring liver transplantation have been reported with prophylactic use. ( 5.3 ) Atovaquone and proguanil hydrochloride tablets have not been evaluated for the treatment of cerebral malaria or other severe manifestations of complicated malaria. Patients with severe malaria are not candidates for oral therapy. ( 5.4 ) 5.1 Vomiting and Diarrhea Absorption of atovaquone may be reduced in patients with diarrhea or vomiting. If atovaquone and proguanil hydrochloride tablets are used in patients who are vomiting, parasitemia should be closely monitored and the use of an antiemetic considered [see Dosage and Administration (2) ]. Vomiting occurred in up to 19% of pediatric patients given treatment doses of atovaquone and proguanil hydrochloride tablets. In the controlled clinical trials, 15.3% of adults received an antiemetic when they received atovaquone/proguanil and 98.3% of these patients were successfully treated. In patients with severe or persistent diarrhea or vomiting, alternative antimalarial therapy may be required. 5.2 Relapse of Infection In mixed P. falciparum and Plasmodium vivax infections, P. vivax parasite relapse occurred commonly when patients were treated with atovaquone and proguanil hydrochloride tablets alone. In the event of recrudescent P. falciparum infections after treatment with atovaquone and proguanil hydrochloride tablets or failure of chemoprophylaxis with atovaquone and proguanil hydrochloride tablets, patients should be treated with a different blood schizonticide. 5.3 Hepatotoxicity Elevated liver laboratory tests and cases of hepatitis and hepatic failure requiring liver transplantation have been reported with prophylactic use of atovaquone and proguanil hydrochloride tablets. 5.4 Severe or Complicated Malaria Atovaquone and proguanil hydrochloride tablets have not been evaluated for the treatment of cerebral malaria or other severe manifestations of complicated malaria, including hyperparasitemia, pulmonary edema, or renal failure. Patients with severe malaria are not candidates for oral therapy.

7 DRUG INTERACTIONS Administration with rifampin or rifabutin is known to reduce atovaquone concentrations; concomitant use with atovaquone and proguanil hydrochloride tablets is not recommended. ( 7.1 ) Proguanil may potentiate anticoagulant effect of warfarin and other coumarin-based anticoagulants. Caution advised when initiating or withdrawing atovaquone and proguanil hydrochloride tablets in patients on anticoagulants; coagulation tests should be closely monitored. ( 7.2 ) Tetracycline may reduce atovaquone concentrations; parasitemia should be closely monitored. ( 7.3 ) 7.1 Rifampin/Rifabutin Concomitant administration of rifampin or rifabutin is known to reduce atovaquone concentrations [see Clinical Pharmacology (12.3) ] . The concomitant administration of atovaquone and proguanil hydrochloride tablets and rifampin or rifabutin is not recommended. 7.2 Anticoagulants Proguanil may potentiate the anticoagulant effect of warfarin and other coumarin-based anticoagulants. The mechanism of this potential drug interaction has not been established. Caution is advised when initiating or withdrawing malaria prophylaxis or treatment with atovaquone and proguanil hydrochloride tablets in patients on continuous treatment with coumarin-based anticoagulants. When these products are administered concomitantly, coagulation tests should be closely monitored. 7.3 Tetracycline Concomitant treatment with tetracycline has been associated with a reduction in plasma concentrations of atovaquone [see Clinical Pharmacology (12.3) ] . Parasitemia should be closely monitored in patients receiving tetracycline. 7.4 Metoclopramide While antiemetics may be indicated for patients receiving atovaquone and proguanil hydrochloride tablets, metoclopramide may reduce the bioavailability of atovaquone and should be used only if other antiemetics are not available [see Clinical Pharmacology (12.3) ] . 7.5 Indinavir Concomitant administration of atovaquone and indinavir did not result in any change in the steady-state AUC and C max of indinavir but resulted in a decrease in the C trough of indinavir [see Clinical Pharmacology (12.3) ] . Caution should be exercised when prescribing atovaquone with indinavir due to the decrease in trough concentrations of indinavir.

6 ADVERSE REACTIONS Prophylaxis: Common adverse reactions (≥ 4%) in adults were diarrhea, dreams, oral ulcers, and headache; these events occurred in a similar or lower proportion of subjects receiving atovaquone and proguanil hydrochloride tablets than an active comparator. Common adverse reactions (≥ 5%) in pediatric patients included abdominal pain, headache, cough, and vomiting. ( 6.1 ) Treatment: Common adverse reactions (≥ 5%) in adolescents and adults were abdominal pain, nausea, vomiting, headache, diarrhea, asthenia, anorexia, and dizziness. Common adverse reactions (≥ 6%) in pediatric patients included vomiting, pruritus, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Mylan at 1-877-446-3679 (1-877-4-INFO-RX) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Because atovaquone and proguanil hydrochloride tablets contain atovaquone and proguanil hydrochloride, the type and severity of adverse reactions associated with each of the compounds may be expected. The lower prophylactic doses of atovaquone and proguanil hydrochloride tablets were better tolerated than the higher treatment doses. Prophylaxis of P.falciparum Malaria In 3 clinical trials (2 of which were placebo-controlled) 381 adults (mean age: 31 years) received atovaquone and proguanil hydrochloride tablets for the prophylaxis of malaria; the majority of adults were black (90%) and 79% were male. In a clinical trial for the prophylaxis of malaria, 125 pediatric patients (mean age: 9 years) received atovaquone and proguanil hydrochloride tablets; all subjects were black and 52% were male. Adverse experiences reported in adults and pediatric patients considered attributable to therapy occurred in similar proportions of subjects receiving atovaquone and proguanil hydrochloride tablets or placebo in all studies. Prophylaxis with atovaquone and proguanil hydrochloride tablets was discontinued prematurely due to a treatment-related adverse experience in 3 of 381 (0.8%) adults and 0 of 125 pediatric patients. In a placebo-controlled study of malaria prophylaxis with atovaquone and proguanil hydrochloride tablets involving 330 pediatric patients (aged 4 to 14 years) in Gabon, a malaria-endemic area, the safety profile of atovaquone and proguanil hydrochloride tablets was consistent with that observed in the earlier prophylactic studies in adults and pediatric patients. The most common treatment-emergent adverse events with atovaquone and proguanil hydrochloride tablets were abdominal pain (13%), headache (13%), and cough (10%). Abdominal pain (13% vs. 8%) and vomiting (5% vs. 3%) were reported more often with atovaquone and proguanil hydrochloride tablets than with placebo. No patient withdrew from the study due to an adverse experience with atovaquone and proguanil hydrochloride tablets. No routine laboratory data were obtained during this study. Non-immune travelers visiting a malaria-endemic area received atovaquone and proguanil hydrochloride tablets (n = 1,004) for prophylaxis of malaria in 2 active-controlled clinical trials. In one study (n = 493), the mean age of subjects was 33 years and 53% were male; 90% of subjects were white, 6% of subjects were black, and the remaining were of other racial/ethnic groups. In the other study (n = 511), the mean age of subjects was 36 years and 51% were female; the majority of subjects (97%) were white. Adverse experiences occurred in a similar or lower proportion of subjects receiving atovaquone and proguanil hydrochloride tablets than an active comparator (Table 3). Fewer neuropsychiatric adverse experiences occurred in subjects who received atovaquone and proguanil hydrochloride tablets than mefloquine. Fewer gastrointestinal adverse experiences occurred in subjects receiving atovaquone and proguanil hydrochloride tablets than chloroquine/proguanil. Compared with active comparator drugs, subjects receiving atovaquone and proguanil hydrochloride tablets had fewer adverse experiences overall that were attributed to prophylactic therapy (Table 3). Prophylaxis with atovaquone and proguanil hydrochloride tablets was discontinued prematurely due to a treatment-related adverse experience in 7 of 1,004 travelers. Table 3. Adverse Experiences in Active-Controlled Clinical Trials of Atovaquone and Proguanil Hydrochloride Tablets for Prophylaxis of P. falciparum Malaria Percent of Subjects with Adverse Experiences Adverse experiences that started while receiving active study drug. (Percent of Subjects with Adverse Experiences Attributable to Therapy) Study 1 Study 2 Atovaquone and Proguanil Hydrochloride Tablets n = 493 (28 days) Mean duration of dosing based on recommended dosing regimens. Mefloquine n = 483 (53 days) Atovaquone and Proguanil Hydrochloride Tablets n = 511 (26 days) Chloroquine plus Proguanil n = 511 (49 days) Diarrhea 38 (8) 36 (7) 34 (5) 39 (7) Nausea 14 (3) 20 (8) 11 (2) 18 (7) Abdominal pain 17 (5) 16 (5) 14 (3) 22 (6) Headache 12 (4) 17 (7) 12 (4) 14 (4) Dreams 7 (7) 16 (14) 6 (4) 7 (3) Insomnia 5 (3) 16 (13) 4 (2) 5 (2) Fever 9 (< 1) 11 (1) 8 (< 1) 8 (< 1) Dizziness 5 (2) 14 (9) 7 (3) 8 (4) Vomiting 8 (1) 10 (2) 8 (0) 14 (2) Oral ulcers 9 (6) 6 (4) 5 (4) 7 (5) Pruritus 4 (2) 5 (2) 3 (1) 2 (< 1) Visual difficulties 2 (2) 5 (3) 3 (2) 3 (2) Depression < 1 (< 1) 5 (4) < 1 (< 1) 1 (< 1) Anxiety 1 (< 1) 5 (4) < 1 (< 1) 1 (< 1) Any adverse experience 64 (30) 69 (42) 58 (22) 66 (28) Any neuropsychiatric event 20 (14) 37 (29) 16 (10) 20 (10) Any GI event 49 (16) 50 (19) 43 (12) 54 (20) In a third active-controlled study, atovaquone and proguanil hydrochloride tablets (n = 110) was compared with chloroquine/proguanil (n = 111) for the prophylaxis of malaria in 221 non-immune pediatric patients (aged 2 to 17 years). The mean duration of exposure was 23 days for atovaquone and proguanil hydrochloride tablets, 46 days for chloroquine, and 43 days for proguanil, reflecting the different recommended dosage regimens for these products. Fewer patients treated with atovaquone and proguanil hydrochloride tablets reported abdominal pain (2% vs. 7%) or nausea (< 1% vs. 7%) than children who received chloroquine/proguanil. Oral ulceration (2% vs. 2%), vivid dreams (2% vs. < 1%), and blurred vision (0% vs. 2%) occurred in similar proportions of patients receiving either atovaquone and proguanil hydrochloride tablets or chloroquine/proguanil, respectively. Two patients discontinued prophylaxis with chloroquine/proguanil due to adverse events, while none of those receiving atovaquone and proguanil hydrochloride tablets discontinued due to adverse events. Treatment of Acute, Uncomplicated P. falciparum Malaria In 7 controlled trials, 436 adolescents and adults received atovaquone and proguanil hydrochloride tablets for treatment of acute, uncomplicated P. falciparum malaria. The range of mean ages of subjects was 26 to 29 years; 79% of subjects were male. In these studies, 48% of subjects were classified as other racial/ethnic groups, primarily Asian; 42% of subjects were black and the remaining subjects were white. Attributable adverse experiences that occurred in ≥ 5% of patients were abdominal pain (17%), nausea (12%), vomiting (12%), headache (10%), diarrhea (8%), asthenia (8%), anorexia (5%), and dizziness (5%). Treatment was discontinued prematurely due to an adverse experience in 4 of 436 (0.9%) adolescents and adults treated with atovaquone and proguanil hydrochloride tablets. In 2 controlled trials, 116 pediatric patients (weighing 11 to 40 kg) (mean age: 7 years) received atovaquone and proguanil hydrochloride tablets for the treatment of malaria. The majority of subjects were black (72%); 28% were of other racial/ethnic groups, primarily Asian. Attributable adverse experiences that occurred in ≥ 5% of patients were vomiting (10%) and pruritus (6%). Vomiting occurred in 43 of 319 (13%) pediatric patients who did not have symptomatic malaria but were given treatment doses of atovaquone and proguanil hydrochloride tablets for 3 days in a clinical trial. The design of this clinical trial required that any patient who vomited be withdrawn from the trial. Among pediatric patients with symptomatic malaria treated with atovaquone and proguanil hydrochloride tablets, treatment was discontinued prematurely due to an adverse experience in 1 of 116 (0.9%). In a study of 100 pediatric patients (5 to < 11 kg body weight) who received atovaquone and proguanil hydrochloride tablets for the treatment of uncomplicated P. falciparum malaria, only diarrhea (6%) occurred in ≥ 5% of patients as an adverse experience attributable to atovaquone and proguanil hydrochloride tablets. In 3 patients (3%), treatment was discontinued prematurely due to an adverse experience. Abnormalities in laboratory tests reported in clinical trials were limited to elevations of transaminases in patients with malaria being treated with atovaquone and proguanil hydrochloride tablets. The frequency of these abnormalities varied substantially across trials of treatment and were not observed in the randomized portions of the prophylaxis trials. One active-controlled trial evaluated the treatment of malaria in Thai adults (n = 182); the mean age of subjects was 26 years (range: 15 to 63 years); 80% of subjects were male. Early elevations of ALT and AST occurred more frequently in patients treated with atovaquone and proguanil hydrochloride tablets (n = 91) compared with patients treated with an active control, mefloquine (n = 91). On Day 7, rates of elevated ALT and AST with atovaquone and proguanil hydrochloride tablets and mefloquine (for patients who had normal baseline levels of these clinical laboratory parameters) were ALT 26.7% vs. 15.6%; AST 16.9% vs. 8.6%, respectively. By Day 14 of this 28-day study, the frequency of transaminase elevations equalized across the 2 groups. 6.2 Postmarketing Experience In addition to adverse events reported from clinical trials, the following events have been identified during postmarketing use of atovaquone and proguanil hydrochloride tablets. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to atovaquone and proguanil hydrochloride tablets. Blood and Lymphatic System Disorders: Neutropenia and anemia. Pancytopenia in patients with severe renal impairment treated with proguanil [see Contraindications (4) ] . Immune System Disorders: Allergic reactions including anaphylaxis, angioedema, urticaria, and vasculitis. Nervous System Disorders: Seizures and psychotic events (such as hallucinations); however, a causal relationship has not been established. Gastrointestinal Disorders: Stomatitis. Hepatobiliary Disorders: Elevated liver laboratory tests, hepatitis, cholestasis; hepatic failure requiring transplant has been reported. Skin and Subcutaneous Tissue Disorders: Photosensitivity, rash, erythema multiforme, and Stevens-Johnson syndrome.

8.1 Pregnancy Risk Summary Available data from published literature and postmarketing experience with use of atovaquone and proguanil hydrochloride tablets in pregnant women are insufficient to identify a drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes. The proguanil component of atovaquone and proguanil hydrochloride tablets acts to inhibit parasitic dihydrofolate reductase; however, pregnant women and females of reproductive potential should continue folate supplementation to prevent neural tube defects [see Clinical Pharmacology (12.4) ] . Pregnant women with malaria are at increased risk for adverse pregnancy outcomes (see Clinical Considerations ) . Atovaquone administered by oral gavage to pregnant rats and rabbits during the period of organogenesis was not associated with fetal malformations at plasma exposures approximately 7 times and equal to, respectively, the estimated human exposure for the treatment of malaria based on AUC. Proguanil administered to pregnant rats and rabbits during the period of organogenesis was not associated with embryo-fetal toxicity at maternally toxic plasma exposures approximately 0.07 and 0.8 times, respectively, the estimated human exposure for treatment of malaria based on AUC (see Data ) . The combination of atovaquone and proguanil hydrochloride given orally by gavage during the period of organogenesis was not associated with embryo-fetal developmental effects in pregnant rats or rabbits at atovaquone:proguanil hydrochloride doses of 50:20 mg/kg/day and 100:40 mg/kg/day, respectively (1.7 and 0.1 times and 0.3 and 0.5 times, respectively, the estimated human exposure for treatment of malaria). In a pre- and post-natal study with atovaquone and another pre- and post-natal study with proguanil, neither compound impaired the growth, development, or reproductive ability of first generation offspring at maternal AUC exposures of approximately 7.3 and 0.04 times, respectively, the estimated human AUC exposure for treatment of malaria (see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Malaria during pregnancy increases the risk for adverse pregnancy outcomes, including maternal anemia, prematurity, spontaneous abortion, and stillbirth. Data Animal Data Atovaquone Atovaquone administered in oral doses of 250, 500, and 1,000 mg/kg/day during organogenesis (Gestation Day [GD] 6 to GD15) in pregnant rats did not cause maternal or embryo-fetal toxicity at doses up to 1,000 mg/kg/day corresponding to maternal plasma exposures up to 7.3 times the estimated human exposure for the treatment of malaria based on AUC. In pregnant rabbits, atovaquone administered in oral doses of 300, 600, and 1,200 mg/kg/day by gavage during organogenesis (GD6 to GD18) was associated with decreased fetal body length at a maternally toxic dose of 1,200 mg/kg/day corresponding to plasma exposures that were approximately 1.3 times the estimated human exposure during treatment of malaria based on AUC. In a pre- and post-natal study in rats, atovaquone administered in oral doses of 250, 500, and 1,000 mg/kg/day from GD15 until Lactation Day (LD) 20 did not impair the growth or developmental effects in first generation offspring at doses up to 1,000 mg/kg/day corresponding to AUC exposures of approximately 7.3 times the estimated human exposure during treatment of malaria. Atovaquone crossed the placenta and was present in fetal rat and rabbit tissue. Proguanil Proguanil administered orally to pregnant rats during organogenesis (GD6 to GD17) was not associated with fetal malformations, but increased ureter variations at a maternally toxic dose of 20 mg/kg/day corresponding to a plasma concentration approximately equal to 0.07 times the estimated human exposure for the treatment of malaria based on AUC. Proguanil given orally by gavage at a maternally toxic dose of 40 mg/kg/day to pregnant rabbits during organogenesis (GD6 to GD20) did not produce adverse embryo-fetal effects at a plasma concentration up to 0.8 times the estimated human exposure for the treatment of malaria based on AUC. In a pre- and post-natal study in female rats, proguanil hydrochloride administered in oral doses of 4, 8, or 16 mg/kg/day from GD6 until LD20 did not impair the growth, development, or reproductive ability of first generation offspring or the survivability of second generation offspring at doses up to 16 mg/kg/day (0.04 times the average human exposure based on AUC). Pre- and post-natal studies of proguanil in animals at exposures similar to or greater than those observed in humans have not been conducted. Atovaquone and Proguanil The combination of atovaquone and proguanil hydrochloride administered orally to pregnant rats in atovaquone:proguanil hydrochloride doses of 12.5:5, 25:10, and 50:20 mg/kg/day during organogenesis (GD6 to GD17) did not produce maternal toxicity or adverse embryo-fetal developmental effects with doses up to 50:20 mg/kg/day corresponding to plasma concentrations up to 1.7 and 0.1 times, respectively, the estimated human exposure during treatment of malaria based on AUC. In pregnant rabbits, the combination of atovaquone and proguanil hydrochloride administered orally in atovaquone:proguanil hydrochloride doses of 25:10, 50:20, or 100:40 mg/kg/day during organogenesis (GD6 to GD20) did not produce adverse embryo-fetal developmental effects at a maternally toxic dose of 100:40 mg/kg/day corresponding to plasma concentrations of approximately 0.3 and 0.5 times, respectively, the estimated human exposure during treatment of malaria based on AUC.