 | |
| Clinical data | |
|---|---|
| ATC code |
|
| Identifiers | |
| |
| CAS Number | |
| PubChem CID | |
| ChemSpider | |
| UNII | |
| ChEMBL | |
| Chemical and physical data | |
| Formula | C19H29N3O |
| Molar mass | 315.461 g·mol−1 |
| 3D model (JSmol) | |
| |
| |
  | |
Pamaquine is an 8-aminoquinoline drug formerly used for the treatment of malaria. It is closely related to primaquine.
Pamaquine is effective against the hypnozoites of the relapsing malarias ( P. vivax and P. ovale ); and unlike primaquine, it is also very effective against the erythrocytic stages of all four human malarias. One small clinical trial of pamaquine as a causal prophylactic was disappointing [3] (whereas primaquine is an extremely effective causal prophylactic).
Pamaquine is more toxic and less efficacious than primaquine; therefore, pamaquine is no longer routinely used, and of the two, only primaquine is currently recommended by the World Health Organization. [4]
Like primaquine, pamaquine causes haemolytic anaemia in patients with G6PD deficiency. Patients should therefore always be screened for G6PD deficiency prior to being prescribed pamaquine.
Pamaquine was the second synthetic antimalarial drug to be discovered (after methylene blue). It was synthesised by Schulemann, Schoenhoeffer and Wingler in 1924. In 1926, Roehl demonstrated that pamaquine was effective in treating malaria in birds, and introduced it into use in humans. [5] Its development is of interest in the history of pharmacotherapy because it was one of the early victories in validating the potential of applying organic chemistry to the synthesis of chemicals that would fight infections with good specificity while presenting adverse effect profiles small enough that benefit would outweigh harm, relative to the contemporary alternative of little to no efficacious treatment for many debilitating diseases. In other words, it expanded the evidence that the hope for great potential of antimicrobial chemotherapy shown by Paul Ehrlich and others was worth pursuing with more research [2] :88–91—and that early wins such as arsphenamine were more than just isolated flukes. This was a time period when organic chemistry's largest economic applications included textile dyes, explosives, munitions, and chemical weapons but not yet pharmaceuticals. The fact that systematic, iterative experiments had eventually synthesized an antimalarial drug that was 30 times more effective than quinine [2] :91 while being safe enough to use (relative to the bleak alternatives of the era) supported the concept of modern pharmaceutical research laboratories as it would develop in coming decades.
A large trial of pamaquine performed by the Royal Army Medical Corps and the British Indian Medical Service in 1929 showed for the first time that it was possible to prevent relapse of vivax malaria. [1] Prior to this, it was understood that patients with vivax malaria would suffer from relapses, but there was no treatment that could prevent the relapses from occurring.
The relative weights of treatment benefit and harm change over decades as science advances. About a decade after pamaquine became available, chloroquine arrived, and about a decade after that, primaquine arrived. Pamaquine is more toxic and less efficacious than primaquine; therefore, pamaquine is no longer routinely used, and of the two, only primaquine is currently recommended by the World Health Organization. [4]
Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause yellow skin, seizures, coma, or death. Symptoms usually begin ten to fifteen days after being bitten by an infected mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.
Mefloquine, sold under the brand name Lariam among others, is a medication used to prevent or treat malaria. When used for prevention it is typically started before potential exposure and continued for several weeks after potential exposure. It can be used to treat mild or moderate malaria but is not recommended for severe malaria. It is taken by mouth.
Antimalarial medications or simply antimalarials are a type of antiparasitic chemical agent, often naturally derived, that can be used to treat or to prevent malaria, in the latter case, most often aiming at two susceptible target groups, young children and pregnant women. As of 2018, modern treatments, including for severe malaria, continued to depend on therapies deriving historically from quinine and artesunate, both parenteral (injectable) drugs, expanding from there into the many classes of available modern drugs. Incidence and distribution of the disease is expected to remain high, globally, for many years to come; moreover, known antimalarial drugs have repeatedly been observed to elicit resistance in the malaria parasite—including for combination therapies featuring artemisinin, a drug of last resort, where resistance has now been observed in Southeast Asia. As such, the needs for new antimalarial agents and new strategies of treatment remain important priorities in tropical medicine. As well, despite very positive outcomes from many modern treatments, serious side effects can impact some individuals taking standard doses.
Glucose-6-phosphate dehydrogenase deficiency (G6PDD) is an inborn error of metabolism that predisposes to red blood cell breakdown. Most of the time, those who are affected have no symptoms. Following a specific trigger, symptoms such as yellowish skin, dark urine, shortness of breath, and feeling tired may develop. Complications can include anemia and newborn jaundice. Some people never have symptoms.
Dapsone, also known as diaminodiphenyl sulfone (DDS), is an antibiotic commonly used in combination with rifampicin and clofazimine for the treatment of leprosy. It is a second-line medication for the treatment and prevention of pneumocystis pneumonia and for the prevention of toxoplasmosis in those who have poor immune function. Additionally, it has been used for acne, dermatitis herpetiformis, and various other skin conditions. Dapsone is available both topically and by mouth.
Artemisinin and its semisynthetic derivatives are a group of drugs used against malaria due to Plasmodium falciparum. It was discovered in 1972 by Tu Youyou, who was co-recipient of the 2015 Nobel Prize in Medicine for her discovery. Treatments containing an artemisinin derivative are now standard treatment worldwide for P. falciparum malaria as well as malaria due to other species of Plasmodium. Artemisinin is isolated from the plant Artemisia annua, sweet wormwood, a herb employed in Chinese traditional medicine. A precursor compound can be produced using a genetically-engineered yeast, which is much more efficient than using the plant.
Artemether is a medication used for the treatment of malaria. The injectable form is specifically used for severe malaria rather than quinine. In adults, it may not be as effective as artesunate. It is given by injection in a muscle. It is also available by mouth in combination with lumefantrine, known as artemether/lumefantrine.
Artesunate (AS) is a medication used to treat malaria. The intravenous form is preferred to quinine for severe malaria. Often it is used as part of combination therapy, such as artesunate plus mefloquine. It is not used for the prevention of malaria. Artesunate can be given by injection into a vein, injection into a muscle, by mouth, and by rectum.
Primaquine is a medication used to treat and prevent malaria and to treat Pneumocystis pneumonia. Specifically it is used for malaria due to Plasmodium vivax and Plasmodium ovale along with other medications and for prevention if other options cannot be used. It is an alternative treatment for Pneumocystis pneumonia together with clindamycin. It is taken by mouth.
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria. Although it is less virulent than Plasmodium falciparum, the deadliest of the five human malaria parasites, P. vivax malaria infections can lead to severe disease and death, often due to splenomegaly. P. vivax is carried by the female Anopheles mosquito; the males do not bite.
8-Aminoquinoline is the 8-amino derivative of quinoline. It is structurally analogous to 8-hydroxyquinoline. The two nitrogen atoms are ideally situated to form complexes with metal ions. Derivatives of 8-aminoquinoline are effective directing groups in organic synthesis.
Malaria prophylaxis is the preventive treatment of malaria. Several malaria vaccines are under development.
Tafenoquine, sold under the brand name Krintafel among others, is a medication used to prevent and to treat malaria. With respect acute malaria it is used together with other medications to prevent relapse by Plasmodium vivax. It may be used to prevent all types of malaria. It is taken by mouth.
The Stateville Penitentiary malaria study was a controlled but ethically questionable study of the effects of malaria on the prisoners of Stateville Penitentiary near Joliet, Illinois in the 1940s. The study was conducted by the Department of Medicine at the University of Chicago in conjunction with the United States Army and the State Department. The Stateville experiment was viewed as coercive because it offered shortened sentences to participants. The study is notable for its impacts on the Nuremberg Medical Trial and subsequent medical experimentation on prisoners.
The history of malaria stretches from its prehistoric origin as a zoonotic disease in the primates of Africa through to the 21st century. A widespread and potentially lethal human infectious disease, at its peak malaria infested every continent, except Antarctica. Its prevention and treatment have been targeted in science and medicine for hundreds of years. Since the discovery of the Plasmodium parasites which cause it, research attention has focused on their biology, as well as that of the mosquitoes which transmit the parasites.
Medicines for Malaria Venture (MMV), a not-for-profit public-private partnership, was established as a foundation in Switzerland in 1999. Its mission is to reduce the burden of malaria in disease-endemic countries by discovering, developing and facilitating delivery of new, effective and affordable antimalarial drugs. Its vision is a world in which these innovative medicines will cure and protect the vulnerable and under-served populations at risk of malaria, and help to ultimately eradicate this terrible disease.
The administration of drugs to whole populations irrespective of disease status is referred to as mass drug administration (MDA).
Warburg's tincture was a pharmaceutical drug, now obsolete. It was invented in 1834 by Dr. Carl Warburg.
Sulfadoxine/pyrimethamine, sold under the brand name Fansidar, is a combination medication used to treat malaria. It contains sulfadoxine and pyrimethamine. For the treatment of malaria it is typically used along with other antimalarial medication such as artesunate. In areas of Africa with moderate to high rates of malaria, three doses are recommended during the second and third trimester of pregnancy.
Piperaquine/dihydroartemisinin (DHA/PPQ), sold under the brand name Eurartesim among others, is a fixed dose combination medication used in the treatment of malaria. It is a combination of piperaquine and dihydroartemisinin. Specifically it is used for malaria of the P. falciparum and P. vivax types. It is taken by mouth.