A detailed overview of Chloroquine will clear out the indications to the drug use, its potential for COVID-19 treatment, safety, contraindications, and possible side effects.
Chloroquine coronavirus. An Old Drug with a New Potential
Chloroquine is a drug intended to treat some types of malaria and amebiasis. It can also be used in patients suffering from certain autoimmune diseases, like lupus and rheumatoid arthritis. However, as of 2020, this preparation is being studied for its potential to cure COVID-19.
How Chloroquine Works
The efficiency of Chloroquine in individuals with chloroquine-sensitive forms of malaria is explained by the ability of the medication to inhibit the vital functions of the parasite cells. It interferes with the normal membrane function thus leading to cell autodigestion.
The use of this preparation in the experimental treatment of patients infected with novel coronavirus is explained by the antiviral properties of Chloroquine. It affects the viral cell pH, which doesn’t allow the virus to release its RNA into the cell, and thus replicate.
How to Take the Drug
Chloroquine is a very serious medication with a whole list of warnings and contraindications. What’s more, the drug can be the reason for numerous adverse reactions, which can get extremely dangerous if it is taken without the doctor’s prescription. Therefore, the first step to a safe intake of Chloroquine is a consultation with a medical specialist. Only if your doctor considers that the potential benefits prevail the possible risks, he/she can give out a prescription for it.
The dosing regimen of the drug depends on the disease treated. In case the medication is used for the prophylaxis of malaria, the scheme of intake gets totally different from the one used to cure this illness. For example, when using Chloroquine as a prophylactic measure, take 500 mg tablet once a week, the same day of the week. It is strongly advised to start the intake two weeks prior to the possible exposure to the parasite.
The therapeutic dose of the medication for the treatment of malaria depends on the patient’s weight. The therapy lasts for only 3 days with different doses of the medication taken each day.
When treating amebiasis, the common dose is 1 g Chloroquine for two days (single daily dose intake). The dose should be halved on the third day of the therapy and remain the same for the rest of two or three weeks of treatment.
The Potential of Chloroquine for COVID-19
Trying to find a cure for the novel coronavirus, the World Health Organization, as well as the US CDC, allowed using some of the already existing drugs as an off-label treatment for this illness. Chloroquine became one of those that have shown positive results in patients with confirmed COVID-19.
Because of the lack of knowledge regarding the effect of the drug on the virus and the absence of common recommendations for its use in this category of patients, it’s up to the medical specialists to decide what dose of Chloroquine to prescribe.
Clinical studies on the efficiency and safety of Chloroquine for COVID-19 treatment are already on the way. They started in January and the first results give hope for the better.
When Chloroquine is not Advised
One of the cases, when Chloroquine can do more harm than benefit, is its use in patients who are hypersensitive or allergic to chloroquine or 4-aminoquinolines. It is strictly contraindicated to prescribe this drug to the patients with the mentioned issues.
The medication can also provoke rapid worsening of certain health conditions, including:
Vision problems (retinopathy).
Therefore, its use in individuals with these health problems is not recommended.
Warnings for the Drug Use
Being a prescription-only drug, Chloroquine may cause more serious side effects in patients with certain health conditions. To reduce the risks, special caution and close monitoring are needed when prescribing Chloroquine to those suffering from:
Kidney or liver dysfunction;
Heart rhythm issues, QT prolongation, in particular.
There exist certain risks for the fetus and breastfed babies if their mothers take Chloroquine. It is recommended to avoid prescribing this medication in these patients. However, if the potential benefits for the mother prevail the possible risks for the baby, this medication can be applied.
The drug can increase your skin sensitivity to the sun. Thus, you should use all the possible protective measures, including sunscreen, hats, and clothes covering the body areas that can be exposed to the sun to avoid sunburns.
What Adverse Reactions to Chloroquine Are Possible
The most commonly experienced side effects of the drug are associated with the gastrointestinal tract. They are the following:
Headaches are also not rare in patients taking Chloroquine. In most cases, these reactions are light-to-moderate in nature and go away on their own. Still, you should inform your attending doctor about them to keep the situation under control.
Unfortunately, the reactions we’ve mentioned above are only a few of all the possible conditions you may develop. Among the severe adverse effects to Chloroquine there are:
Changes in the blood sugar level;
Upper respiratory infection signs;
Slowed heart rhythm, QT prolongation;
Symptoms of heart failure;
Mood swings, depression;
Ringing in the ears (rarely, hearing loss).
The list can be continued but you’d better discuss it with your healthcare provider. Any of the listed reactions is a reason to call 911 or go to the nearest clinic.
One of the factors determining the severity of adverse reactions you may experience is your general health condition. Also, the intake of certain medications or shortage of some nutrients (magnesium or potassium) can trigger more severe adverse reactions than in other patients taking Chloroquine. Therefore, informing your doctor about all the drugs and herbal products you use is crucial.