Anas Raed. - Zaid Emad. - Malik Zuhlof

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1 - 6 - Anas Raed - Zaid Emad - Malik Zuhlof 1 P a g e

2 - This lecture started with the excellent presentation of chronic fatigue syndrome and the role of Vitamin B12 in its treatment by our colleague Osama Alzoubi.The doctor added that patients with chronic fatigue syndrome take vitamin B12 supplements even if they don t have vitamin B12 deficiency, as somehow it improves their status. - These patients are too stressful, especially women at the age of 30-50, some scientists have linked that to abnormalities in cortisol (the endocrine hormones), so, instead of giving vitamin B12, we reduce the stress by giving anti-depressants* (selective serotonin re-uptake inhibitors), which results in better activity and we ll treat this syndrome. *It will be discussed later in the CNS. Now we ll continue talking about MALARIA. *The doctor read most of the slides very quickly, so, I ll try to do my best. *Anything in red was found in the slide but not mentioned by the doctor. Anti-malarial agents: Chloroquine: - It is a potent blood schizontocidal drug (kill the parasite during its part of the life cycle within the RBC) effective against all four types of clinically important plasmodium species. - It is accumulated in parasite lysosomes. - Chloroquine inhibits digestion of haemoglobin by the parasite and thus helps reduce its supply of amino acids. - Chloroquine inhibits haem polymerase that is responsible for the transformation of the free haem into haemozoin that s beneficial for the parasite, which means accumulating the toxic free haem within the RBC, thus killing the infected cell with the offending parasite. - We give one tablet weekly because it has a long tissue half-life, so it will establish a reservoir and we ll end up with a sustained release. - Adverse effects: 1- Gastrointestinal upset..)حكة( 2- Pruritus 3- Headaches. 4- Visual disturbances (an ophthalmological examination should be routinely performed).. important. 2 P a g e

3 5- Hypotension, cardiac arrhythmia and convulsions if given parenterally (IV). - Chloroquine is the drug of choice in the treatment of erythrocytic falciparum malaria, except in resistant strains. - This resistance is done by pumping the drug out of the lysosome, so we give another drug that is not a substrate for the pump which is Mefloquine. - Long-term usage of Mefloquine may result in cardiac arrest, so we use it in prophylaxis not in treatment because it s very toxic and have many side effects..)داء الصدف( - Chloroquine contraindications: psoriasis or porphyria - Chloroquine is less effective against vivax malaria. - It is also effective in the treatment of extraintestinal amebiasis. - It is used for the treatment of malaria in pregnancy. Quinine and Quinidine: - They re more toxic and less effective than Chloroquine and Mefloquine against malarial parasites but due to their CNS penetration we give them for patients with cerebral malaria or in cases of severe malaria. - Therapeutic dosages of quinine and quinidine commonly cause tinnitus, headache, nausea, dizziness, flushing, and visual disturbances this collection of symptoms termed cinchonism. - They are rapid-acting, highly effective blood schizonticide against the four species of human malaria parasites. - The drug is gametocidal against P vivax and P ovale but not P falciparum. It is not active against liver stage parasites. - Therapeutic doses may cause hypoglycaemia through stimulation of insulin release (pregnant patients). - Quinine can raise plasma levels of warfarin and digoxin. Atovaquone-proguanil)Malarone): - It s a weak drug. - It s a combination of two drugs (Atovaquone and proguanil), so it has two mechanisms of action, reducing the chances of developing resistance against this drug, as it s not a substrate for the pump. - Currently, its recommended as the drug of choice in prophylaxis against malaria. 3 P a g e

4 Proguanil (Chloroguanide): - It is a slow-acting erythrocytic schizonticide, also inhibits the preerythrocytic stage of P. Falciparum. - MOA: it is converted in the body to cycloguanil that inhibits the plasmodial enzyme dihydrofolate reductase without affecting the mammalian enzyme thus it inhibits the parasitic DNA synthesis (the same MOA as Methotrexate). - Current use of proguanil is restricted to prophylaxis of malaria in combination with chloroquine(or Atovaquone) in areas of low level of chloroquine resistance among P.falciparum. Mefloquine: - Mefloquine is effective chemo-prophylactic drug for many chloroquine resistant strains of P. falciparum and against other species. - Its mechanism of action appears to be associated with inhibition of the haem-polymerase (same mechanism as chloroquine). - Weekly dosing with mefloquine for chemoprophylaxis may cause: nausea, vomiting, sleep and behavioural disturbances, epigastric pain, diarrhea, abdominal pain, headache, rash, dizziness and Neuropsychiatric toxicities. - It is contraindicated in a patient with a history of epilepsy, psychiatric disorders, arrhythmia, and cardiac conduction defects. - As we said before we can t take Mefloquine on a long term basis as it can result in cardiac arrest. Primaquine (this drug was not mentioned by the doctor at all, but we found it in the slides!! so I think that reading the information below is enough ) - It destroys primary and latent hepatic stages of P. vivax and P. ovale, thus it has great clinical value for preventing relapses of P. vivax or P. ovale malaria (Standard therapy). - It exerts a marked gametocidal effect against all four species of plasmodia that infect humans, especially P. falciparum. - Because of its lack of activity against the erythrocytic schizonts, primaquine is often used in conjunction with a blood schizonticide. - It can cause haemolytic anaemia in patients with genetically low levels of glucose-6-phosphate dehydrogenase. 4 P a g e

5 - Patients should be tested for G6PD deficiency before primaquine is prescribed. - Side effects: nausea, epigastric pain, abdominal cramps, and headache These symptoms are more common with higher dosages and when the drug is taken on an empty stomach. - Primaquine should be avoided in: 1. Patients with a history of granulocytopenia or methemoglobinemia. 2. In those receiving potentially myelosuppressive drugs (e.g., quinidine). 3. In pregnancy. 4. In G6PD deficiency. Artemisinin derivatives: (Artemether / Arteether / Artesunate) - It is a potent and rapidly acting blood schizontocide with a short duration of action. - Recrudescence rate (recurrence of the disease) is high when used alone in short courses, so its used only in combination (Artemisinin Combination Therapy (ACT)).Also, this combination prevents the emergence of resistance toward this effective drug. - Artemisinins reduce the parasite burden rapidly. - It was discovered in the plant (Artemisia annua- sweet wormwood). - Mechanism of action: instead of forming beta-haematin dimers, this drug will form Haem-Artemesinin adducts (Haemarts) which cannot be bio-mineralized to Haemozoin. 5 P a g e

6 Pyrimethamine-sulphonamide and antibiotics: - Pyrimethamine inhibits plasmodial dihydrofolate reductase at much lower concentrations than those that inhibit the mammalian enzyme. - Tetracycline and doxycycline are active against erythrocytic schizonts of all human malaria parasites. They are not active against liver stages. - Doxycycline is used in the treatment of falciparum malaria in conjunction with quinine, allowing a shorter and better tolerated course of that drug. Drug Chloroquine Atovaquoneproguanil (Malarone) Mefloquine Doxycycline Primaquine Artemisinin Combination therapy Quinine or Quinidine Use Areas without resistant P falciparum (in Africa for prophylaxis and treatment) Areas with chloroquine-resistant P falciparum (in Asia for prophylaxis) Areas with chloroquine-resistant P falciparum (in Asia for prophylaxis)be careful of side effects Areas with multidrug-resistant P falciparum (can be used in Artemisinin combination therapy) Terminal prophylaxis of P.vivax and P.ovale infections; alternative for primary prevention In Asia for the treatment of drug resistant malaria. In Africa for the treatment of cerebral malaria or very severe cases of malaria. 6 P a g e

7 This table was found in the slides, I think it isn t so important but I will put it here for anyone who wanna benefit Clinical Setting Drug Therapy Alternative Drugs Severe or complicated infections with P. falciparum Artesunate, 2.4 mg/kg IV, every 12 hours for 1 day, then daily for two additional days ; follow with 7 day oral course of doxycycline or clindamycin or full treatment course of mefloquine or Malarone OR Quinidine gluconate, 10 mg/ kg IV over 1 2 hours, then 0.02 mg/kg IV/min OR 15 mg/kg IV over 4 hours, then 7.5 mg/kg IV over 4 hours every 8 hours Artemether, 3.2 mg/kg IM, then 1.6 mg/kg/d IM; follow with oral therapy as for Artesunate At the end of this lecture the doctor started talking about anticancer drugs but without slides :/ so everything regarding this topic will be introduced in the next sheet inshallah Feel free to contact me if you have any question regarding this lecture. Good Luck & sorry for any mistakes : ) 7 P a g e

Malaria. is a mosquito-born disease causing about 3 million deaths a year world-wide. Many are children under the age of 5.

Malaria. is a mosquito-born disease causing about 3 million deaths a year world-wide. Many are children under the age of 5. Malaria is a mosquito-born disease causing about 3 million deaths a year world-wide. Many are children under the age of 5. The parasite is transmitted by bites from the female anopheles mosquito. Currently,