HCQS is the abbreviation for the drug hydroxychloroquine. It is indicated for rheumatoid arthritis, gout and autoimmune disease such as lupus. It is derived from chloroquine which is a well-known malarial drug and is active against malarial parasites plasmodium vivax, falciparum, malariae and ovale.
It is also used both as a preventative agent as well as treatment in malaria where there is non-resistance to chloroquine.
Due to the adjustment to the chemical structure of its parent molecule, anti-inflammatory and anti-thrombotic properties were noted. As a result, it was touted as an option for Covid-19 which was later discovered otherwise.
During the initial days of the pandemic, fear of the unknown of the Covid-19 disease created pressure on the global health authorities for a cure, causing premature release of optimistic data from preclinical trials which led to the unproven use of HCQS and azithromycin as the treatment regimen.
The demand for HCQS escalated during the period March to April 2020 but gradually tapered off in the subsequent months as new evidence on the epidemiology of the disease unfolded. However, Emergency Use Authorization (EUA) was already issued but discrepancies with the in vivo and in vitro phenotype revoked the EUA on June 15, 2020 by the FDA (Food and Drug Administration) after safety issues were noticed. Subsequently, it was emphasized that HCQS is not indicated for Covid-19.
The mechanism of action of HCQS inhibit the cytokine production in the inflammatory processes of the body’s immune system where it perceives its own organs as the invader.
This drug is presented in oral formulation as a film coated tablet. The pharmacokinetic profile of HCQS shows high bioavailability (74 percent) after rapid absorption; it is best when taken with a meal since gastric irritation is likely to occur.
The dosage of hydroxychloroquine varies according to disease conditions so:
• In Lupus patients, the dosage ranges from 200mg to 400mg with a daily maintenance of 200mg, depending on the prescriber’s discretion whilst monitoring patient for side effects
• In rheumatoid arthritis the doctor slides the dose according to patient’s response and individual patient profile from the minimum to maximum dosage of 600mg daily, then back to the maintenance dose of 200mg
• In malaria treatment, starting dose is loaded at 800mg followed by 400mg at six hours after, 24 hours after, then 48 hours after in conjunction with another drug, primaquine
• In malaria prophylaxis, patients may commence one or two weeks before, and four weeks after visiting a malarial prone location where dosage is 400mg weekly
This drug crosses the placental barrier and so there is a small risk of malformations of the fetus when used during the first trimester which is associated with dosage as cautioned by a ‘Harvard’ publication in June 2022.
HCQS is classified as pregnancy category D, which is only to be used with extreme caution. But it is worthy to note that no increase risk in spontaneous abortion, prematurity or intrauterine restriction was suggested by a September 2020 study in the American Journal of Obstetrics and Gynecology, which referenced studies dating back to 1996.
So only if the benefits outweigh the risks for a pregnant mother with an autoimmune disease or malaria (either treatment or prevention), HCQS may be considered at the minimum therapeutic dosage from the second trimester.
Note that this drug is approved for use in infants and children with JRA (juvenile rheumatoid arthritis) and SLE (systemic lupus erythematosus), closely monitoring children with renal impairment.
Antacid or diarrheal medications which have magnesium or aluminum and kaolin respectively may affect the absorption of HCQS and so it is recommended not to take such medications concomitantly but wait for a period of four hours.
The most serious side effect profile with prolonged use is retinopathy so frequent eye assessments are required. The American Academy of Ophthalmology recommends screening for retinopathy prior to initiation of treatment with HCQS and then annual screening after five years of maintenance dose.
HCQS may precipitate severe psoriasis in patients suffering with the disease. At higher or prolonged dosages, it may cause drug induced cardiomyopathy or prolong the QT interval in patients leading to ventricular arrhythmia. Milder side effects such as muscle weakness, nervous system and skin effects, may be experienced.
For further discussion, contact the pharmacist of Medicine Express Pharmacy located at 223 Camp Street, between Lamaha and New Market Streets. If you have any queries, comments or further information on the above topic, kindly forward them to medicine.express@gmail.com or send them to 223 Camp Street, N/burg. Tel: 225-5142.
