Action and Spectrum

Actions and Spectrum: 

quinine has several pharmacological actions, including antimalarial, anti-inflammatory, and antiarrhythmic properties. 

Antimalarial action: quinine is a potent antimalarial medication that is effective against all stages of the malaria parasite’s life cycle. It interferes with the ability of the parasite to break down and use hemoglobin, leading to its death. quinine is typically used in combination with other antimalarial medications to prevent the development of resistance. 

Anti-inflammatory action: quinine has been shown to have anti-inflammatory properties, which may be useful in the treatment of conditions such as rheumatoid arthritis and lupus. It works by inhibiting the production of cytokines, which are proteins that play a key role in the inflammatory response. 

Antiarrhythmic action: quinine is also used as an antiarrhythmic medication, particularly in the treatment of atrial fibrillation. It works by blocking the flow of potassium ions in cardiac cells, which can help to stabilize the heart’s rhythm. 

Spectrum of activity: quinine is primarily effective against the malaria parasite, but it may also be used to treat other conditions, such as babesiosis and nocturnal leg cramps. However, its use in these conditions is less common and is typically reserved for cases that have not responded to other treatments. 

Drug Interaction

Adverse Reaction

Frequency Defined 

<1% 

Flushing of the skin 

Fever 

Anginal symptoms 

Rash 

Hypoglycemia 

Epigastric pain 

Pruritus 

Hemolysis  

Thrombocytopenia 

Night blindness 

Diplopia 

Hepatitis 

Optic atrophy 

Hypersensitivity reaction 

Impaired hearing 

Frequency not Defined 

Severe headache 

Blurred vision 

Vomiting 

Diarrhea 

Nausea 

Black Box Warning

Black Box Warning: 

The drug is limited to the treatment of nocturnal leg cramps. 

Serious/life-threatening reactions may occur, like hemolytic uremia and thrombotic thrombocytopenic purpura. 

Thrombotic thrombocytopenic purpura can be caused in case of hepatic or renal impairment.  

Contraindication / Caution

Contraindication/Caution: 

Contraindications: 

• Hypersensitivity to quinine: If a person is allergic to quinine or any of its components, they should not take this medication. 
• Glucose-6-phosphate dehydrogenase deficiency: quinine can cause hemolysis (destruction of red blood cells) in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. 
• Tinnitus: People who have experienced tinnitus (ringing in the ears) after taking quinine should not take it again. 
• Myasthenia gravis: quinine can worsen muscle weakness in people with myasthenia gravis, a neuromuscular disorder. 
• Prolonged QT interval: quinine can prolong the QT interval in the heart, which can lead to dangerous arrhythmias (irregular heartbeats). 

Caution: 

• Pregnancy and breastfeeding: quinine can cross the placenta and enter breast milk, so it should be used with caution in pregnant and breastfeeding women. 
• Hepatic impairment: quinine is metabolized in the liver, so individuals with hepatic impairment should use it with caution. 
• Renal impairment: quinine is eliminated through the kidneys, so individuals with renal impairment should use it with caution. 
• Cardiovascular disease: quinine can cause arrhythmias, so it should be used cautiously in people with cardiovascular disease. 
• Concurrent use of other medications: quinine shows varied drug-drug interactions, and one should inform their healthcare provider before taking the medication. 

Pregnancy / Lactation

Pregnancy consideration:  

Not suitable for pregnant females 

Breastfeeding warnings:  

Lactating mothers should not breastfeed during the therapy 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: No evidence of risk to the fetus is found in animal reproduction studies, and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for a human product; Pregnant women must take care of the potential risks. 
• Category D: There is adequate data with sufficient evidence of human fetal risk from various platforms. However, despite potential dangers may be used only in emergencies for potential benefits. 
• Category X: Drugs listed in this category outweigh the risks over benefits. The drug is not for pregnant women. 
• Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology: 

The pharmacology of quinine involves several mechanisms of action: 

• Inhibition of heme polymerization: quinine prevents the polymerization of heme, a toxic byproduct of the malaria parasite’s metabolism, which is essential for the parasite’s survival. 
• Inhibition of nucleic acid synthesis: quinine inhibits the synthesis of nucleic acids, such as DNA and RNA, which are essential for the growth and replication of the malaria parasite. 
• Alkalization of the parasite’s digestive vacuole: quinine raises the pH of the parasite’s digestive vacuole, which disrupts its ability to digest hemoglobin and other proteins. 
• Disruption of membrane function: quinine disrupts the function of the parasite’s membrane, which affects its ability to transport nutrients and waste products. 

Pharmacodynamics: 

The pharmacodynamics of quinine refers to its actions and effects on the body. quinine is primarily used as an antimalarial medication, and its pharmacodynamic effects are related to its ability to interfere with the growth and replication of the malaria parasite within the red blood cells. 

quinine works by inhibiting the polymerization of heme, a toxic byproduct of the malaria parasite’s metabolism, which is essential for the parasite’s survival. This results in the accumulation of toxic heme within the parasite, leading to its death. quinine also disrupts the function of the parasite’s membrane and its ability to transport nutrients and waste products. 

In addition to its antimalarial effects, quinine has other pharmacodynamic effects as well. It is a mild analgesic and antipyretic, which means it can help to reduce pain and fever. It has been used to treat leg cramps and other muscle spasms, although the mechanism by which it exerts these effects is not well understood.  

Pharmacokinetics: 

Absorption 

The drug is readily absorbed primarily from the upper small intestine 

The protein-bound is 70-95% 

Distribution 

The peak plasma concentration is achieved in 1-3 hours 

Metabolism 

The primarily undergoes hepatic metabolism 

Elimination and Excretion 

The elimination half-life for children is 6-12 hours, and for adults, it is 8-14 hours 

The drug is excreted in feces, saliva, and urine (less than 5% as an unchanged drug) 

Adminstartion

Administration: 

quinine is usually administered orally in the form of tablets or capsules. The exact dosage and duration of treatment depend on the severity and type of malaria infection, as well as the patient’s age, weight, and other medical conditions.  

quinine can also be administered intravenously in the hospital setting for severe cases of malaria or in cases where oral administration is not possible. Intravenous quinine is given slowly over several hours and may require close monitoring of the patient’s heart function and blood glucose levels. 

It is important to take quinine with optimum water or food to minimize the risk of gastrointestinal side effects such as nausea and vomiting. It is also important to avoid taking quinine with other QT-prolongers, as this can increase the risk of dangerous arrhythmias. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: quinine 

Pronounced: KWYE-nine 

Why do we use quinine? 

quinine is primarily used as an antimalarial medication, and it has been used for centuries to treat and prevent malaria.  

quinine is particularly useful in the treatment of cases of malaria that is caused by Plasmodium falciparum, which is the deadliest form of malaria. It is also used to prevent malaria in individuals who are traveling to areas where the disease is endemic. 

In addition to its antimalarial effects, quinine has some other pharmacological effects as well. It is a mild analgesic and antipyretic, and it has been used in the treatment of leg cramps and other muscle spasms. It also has some antiparasitic activity against other protozoal infections, such as babesiosis and trypanosomiasis.