アルテメテル

A 2025 systematic review notes that Artemether and Arteether have a more neurotoxic profile than Artesunate. Artemether induced substantial and frequently irreversible neurotoxic injury in a mouse model in contrast to Artesunate's lower incidence of neurotoxic effects which were reversible.

/CASE REPORTS/ A total of 83 pregnant women with Plasmodium falciparum malaria, administered artesunate or artemether, often followed by quinine or mefloquine, were followed weekly until delivery. Overall 73 pregnancies (88%) resulted in live births, 3 (4%) in abortions, and 2 (3%) in still births. There were no congenital abnormalities and the 46 children followed for more than a year all developed normally

/EPIDEMIOLOGY STUDIES/ Cardiotoxicity has become a major concern during treatment with antimalarial drugs. Lengthening of the QTc and severe cardiac arrhythmia have been observed ... The purpose of this prospective study was to evaluate whether antimalarial agents alter dispersion of the QTc and ventricular repolarization dynamicity. Sixty patients with uncomplicated falciparum malaria were randomly allocated in four groups of 15 patients and treated with quinine, mefloquine, artemether, or halofantrine at recommended doses. Patients in treatment groups were compared with a group including 15 healthy controls with no history of malaria and/or febrile illness within the last month. QTc dispersion was measured on surface electrocardiograms. Repolarization dynamicity was analyzed from Holter recordings, which allow automatic beat-to-beat measurement of QT and RR intervals. Plasma drug concentration was determined by reversed-phase high-performance liquid chromatography. No change in QTc dispersion was observed after treatment with quinine, mefloquine, or artemether. ... Mefloquine and artemether did not alter ventricular repolarization. Quinine induced a significant decrease in QT/RR slope of the same order of magnitude as those previously observed with quinidine. ...

/EPIDEMIOLOGY STUDIES/ A meta-analysis using individual patient data from randomized controlled trials comparing artemether and quinine in severe falciparum malaria /was conducted/. Eleven trials were identified, of which 8 were clearly randomized. Original individual patient data on 1919 patients were obtained from 7 trials, representing 85% of the patients in the original 11 studies. Overall there were 136 deaths among the 961 patients treated with artemether, compared with 164 in the 958 treated with quinine [14% vs 17%, odds ratio (95% confidence interval) 0.8 (0.62 to 1.02), P = 0.08]. There were no differences between the 2 treatment groups in coma recovery or fever clearance times, or the development of neurological sequelae. However, the combined 'adverse outcome' of either death or neurological sequelae was significantly less common in the artemether group [odds ratio (95% CI) 0.77 (0.62 to 0.96), P = 0.02], and treatment with artemether was associated with significantly faster parasite clearance [hazard ratio (95% CI) 0.62 (0.56 to 0.69), P < 0.001]. In subgroup analyses artemether was associated with a significantly lower mortality than quinine in adults with multisystem failure. In the treatment of severe falciparum malaria artemether is at least as effective as quinine in terms of mortality and superior to quinine in terms of overall serious adverse events. There was no evidence of clinical neurotoxicity or any other major side-effects associated with its use.

/EPIDEMIOLOGY STUDIES/ A recent report from Mozambique described a small but significant and irreversible hearing loss in patients exposed to artemether-lumefantrine. To explore this issue, we conducted a case-control study using tympanometry, audiometry and auditory brain-stem responses. We assessed 68 subjects who had been treated with artemether-lumefantrine within the previous five years and 68 age- and sex-matched controls living in the malarious region along the Thailand-Myanmar border. There were no differences in the test results between cases and controls. There was no neurophysiologic evidence of auditory brainstem toxicity that could be attributed to artemether-lumefantrine in this study population.

Drug-Induced Liver Injury Severity and Toxicity (DILIst)

Artemether

DILI Negative

Oral

DOI:10.1016/j.drudis.2019.09.022

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ The artemisinin derivative beta-artemether, an anti-malarial, was evaluated for its toxicity and tolerability in a 2-week, multiple-dose study in dogs. Eight beagle dogs (4 females, 4 males) were given beta-artemether by oral gavage 3 times daily at 45 mg/kg/dosing (a total daily dose-level of 135 mg/kg) for 2 weeks. This beta-artemether dose regime was well tolerated. Body weight changes were normal although feed consumption during the treatment period reduced compared to that of the pre-trial period. Clinical signs were transient spells of soft to liquid feces. On completion of the treatment period, the animals were sacrificed and submitted to a full macroscopic post-mortem examination. Designated organs were weighed and a complete light microscopic examination was performed on 43 selected tissues from 1 animal per sex, and on the liver, kidneys, thymus, mandibular lymph nodes and lungs of the three other animals per sex. Major findings were high liver weight and histopathologic findings of slight diffuse hepatocellular hypertrophy and distal tubular dilatation, together with flattened epithelium, in the kidneys. With the dose regime used in this trial beta-artemether produced no clinical or apparent histopathological signs of neurotoxicity in dogs.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ In view of concern about the potential long-term toxicity, rats were treated orally with 80 mg/kg artemether once every 2 weeks for 5 months. After the final treatment, routine blood test results were normal except for reversible reductions of reticulocyte counts and reversible increases in hemoglobin levels. Liver and kidney function and histopathological examination showed no differences between treated and untreated rats. Administration of 400 mg/kg artemether resulted in transient focal vesicle degeneration of the liver or slight damage to the proprius layer lamina of intestinal villi. No damage to the central nervous system tissues, including cerebrum, cerebellum, midbrain, thalamus, pons, medulla oblongata, and spinal cord, was seen at either concentration. There were no alterations in electrocardiograms during the 6-month treatment period. We conclude that 80 mg/kg artemether administered once every 2 weeks is safe, and doses of 400 mg/kg do not result in evidence of neurotoxicology.

/LABORATORY ANIMALS: Neurotoxicity/ ... Previous animal safety studies with Qinghaosu derivatives revealed dose-dependent neurotoxicity with movement disturbances and neuropathic changes in the hindbrain of intramuscularly treated dogs, rats and monkeys. Such effects have not been seen in /humans/. The objective of the present studies was to compare the effects of high levels of AM administered to dogs p.o. versus i.m. In a pilot study 20 mg/kg/day of AM was given i.m. to groups of 3 male Beagle dogs for 5 and 30 days, respectively. Clinical signs of neurotoxicity were noted in some individual dogs from test day 23 on. One dog had to be sacrificed pre-term. Hematologic findings indicated a hypochromic, microcytic anemia. Microscopic examination demonstrated neuropathic changes only at 30 days, but not at 5 days. The animals had neuronal and secondary axonal damage, most prominent in the cerebellar roof, pontine and vestibular nuclei, and in the raphe/paralemniscal region. The affected neurons showed loss of Nissl substance, cytoplasmic eosinophilia, shrinkage of the nucleus and in advanced stages scavenging by microglia. In a subsequent experiment, AM was administered to groups of 4 male and 4 female dogs, respectively, at 8 daily doses of 0, 20, 40 and 80 mg/kg i.m., or 0, 50, 150 and 600 mg/kg p.o. Neurologic signs were seen at high i.m. doses only. In most animals they were inconspicuous and consisted of reduced activity with convulsions seen in single dogs shortly before death. Neuronal damage occurred in all animals at 40 and 80 mg/kg following i.m. treatment. At 20 mg/kg minimal effects occurred in 5/8 dogs only, indicating that this level was close to tolerated exposure. No comparable lesions were observed after oral administration. Both i.m. and p.o. exposure at high dose levels was associated with a prolongation of mean QT interval of ECG, suggesting slowing of repolarization of the myocardium. Individual data indicated that in 1 of 4 females at 80 mg/kg i.m. this prolongation was above the 25% level considered as threshold for concern. ...

/LABORATORY ANIMALS: Neurotoxicity/ Intramuscular administration of high doses of artemether and arteether to experimental mammals produces selective damage to brain stem centers involved predominantly in auditory processing and vestibular reflexes. The relationship between clinical signs of neurotoxicity and neuropathologic toxicity was studied in the mouse. Intramuscular artemether (50-100 mg/kg/day for 28 days) caused dose-dependent neuropathologic damage to the brain stem. There was no pathologic evidence of neuronal death in mice receiving either oral artemether, or oral or intramuscular artesunate, in doses up to 300 mg/kg/day. The neurons in the lower brain stem trapezoid nucleus, the gigantocellular reticular nucleus, and the inferior cerebellar peduncle were the most sensitive to the toxic effects of artemether. All mice with neuropathologic changes also showed behavioral changes, whereas in some mice with gait disturbance, no corresponding histopathologic damage could be detected. Thus clinical assessment was a sensitive measure of neurotoxicity. There may be a reversible component to artemether neurotoxicity.

/GENOTOXICITY/ Dihydroartemisinin administered orally to rats at 100 mg/kg for 5, 10, or 15 doses was not mutagenic and did not produce chromosome aberrations in bone marrow or testicular cells. /Dihydroartemisinin/

While data specific to artemether were not located(SRC, 2006), the literature suggests that some pharmaceutically active compounds originating from human and veterinary therapy are not eliminated completely in municipal sewage treatment plants and are therefore discharged into receiving waters(1). Wastewater treatment processes often were not designed to remove them from the effluent(2). Selected organic waste compounds may be degrading to new and more persistent compounds that may be released instead of or in addition to the parent compound(2). Studies have indicated that several polar pharmaceutically active compounds can leach through subsoils(1).

Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

Artemether

3.7

15.8

Artemether is given in combination with lumefantrine in a tablet form (COARTEM tablets). COARTEM tablets should be administered over 3 days for a total of 6 doses: an initial dose, second dose after 8 hours, and then twice-daily (morning and evening) for the following 2 days. The adult dosage for patients with bodyweight of 35 kg and above is 4 COARTEM tablets per dose for a total of 6 doses over 3 days. COARTEM tablets are scored and contain 20 mg artemether and 120 mg lumefantrine.

Data used to generate the benchmarks include the following: Lowest Daily Dose (LDD): 160 mg/day, Lowest Therapeutic Dose (LTD): 2.0 mg/kg-day, and Screening Dose: 0.0007 mg/kg-day.

7-Jun-22

Artemether, 1.6 +/- 0.7 and 2.2 +/- 1.9 hr; Dihydroartemisinin, 1.6 +/- 0.6 and 2.2 +/- 1.5 hr

Artemether ... /is/ converted to dihydroartemisinin ... which rapidly disappears from plasma with a half-life of about 45 min.

Rapidly metablized to its active metabolite, dihydroartemisinin.

Artemether ... /is/ converted to dihydroartemisinin ... The antimalarial effect of artemisinin compounds results primarily from dihydroartemisinin ...

Artemisinin is completely and rapidly absorbed after oral administration in rats. However, a very low plasma level was obtained even after a dose of 300 mg/kg. Liver was found to be the chief site of inactivation. When artemisinin was given i.m., significant and more persistent plasma levels were detected. Artemisinin was shown to pass the blood-brain and blood-placenta barriers after i.v. injection. Very little unchanged artemisinin was found in the urine or feces in 48 hours regardless of the route of administration. Metabolites identified after administration to humans include deoxyartemisinin, deoxydihydroartemisinin, and 9,10-dihydroxydeoxyartemisinin. /Artemisinin/

C7D6T3H22J

ARTEMETHER

Established Pharmacologic Class [EPC] - Antimalarial

Artemether is an Antimalarial.

Food increases absorption.

Little or none of the administered drugs or dihydroartemisinin is recovered in urine. /Dihydroartemisinin/

After intramuscular administration pharmacokinetics indicated peak plasma levels of artemether (AM) at 2 to 4 hours post-dose, slow elimination and a tendency to accumulate after repeated administration. Only low levels of the major metabolite, dihydroartemisinin (DHA), were found. AM levels in the cerebrospinal fluid (CSF) were < 10% of plasma levels. After oral administration AM concentrations were considerably lower than after i.m. administration. The concentration of DHA was high on day 1 but almost nil on day 7 indicating its fast inactivation in dogs. Two hours after the 8th oral administration neither AM nor DHA was detected in CSF which may explain the absence of neurotoxicity in dogs after oral administration of AM.

The pharmacokinetics of intramuscular artemether and its major plasma metabolite-dihydroartemisinin, were investigated in patients with severe manifestations of falciparum malaria. Six severe falciparum malaria patients with acute renal failure (ARF) and 11 without ARF were recruited into the study. They were treated with intramuscular artemether at a loading dose of 160 mg, followed by daily doses of 80 mg for another 6 days (total dose 640 mg). Patients with and without ARF showed a good initial response to treatment; the parasite and fever clearance times were 66 (30 to 164) and 76 (36 to 140) hr (median (range)), respectively. None had reappearance of parasitaemia in their peripheral blood smear within 7 days of initiation of treatment. In comatose patients, the time to recovery of consciousness was 51.6 (22 to 144) hr. Artemether was detected in plasma as early as 1hr after a 160 mg dose, and declined to undetectable levels within 24 hr in most cases. Patients with ARF had significantly higher Cmax (2.38 (1.89 to 3.95) vs 1.56 (1.05 to 3.38) ng/mL/mg dose), and lower Vz/F (5.45 (3.2 to 6.9) vs 8.6 (4.2 to 12.3) L/kg) and CL/F (7.4 (5.4 to 13.8) vs 19.1 (8.5 to 25.1) mL/min/kg) when compared to those without ARF. In addition, t1/2z, was significantly longer in ARF patients (7.0 (5.5 to 10.0) vs 5.7 (4.2 to 6.6) hr). The parmacokinetics of dihydroartemisinin in the two groups were comparable. ARF significantly modified the pharmacokinetics of intramuscular artemether. The changes could be contributed to either improved absorption/bioavailability, a reduction of systemic clearance, or a change in plasma protein binding of the drug.

Dihydroartemisinin is rapidly absorbed following oral administration, reaching peak levels after around 2.5 hr. Absorption via the rectal route is somewhat slower, with peak levels occurring around 4 hr after administration. Plasma protein binding is around 55%. Elimination half-life is approximately 45 min via intestinal and hepatic glucuronidation. /Dihydroartemisinin/

For more Absorption, Distribution and Excretion (Complete) data for ARTEMETHER (6 total), please visit the HSDB record page.