As people are stocking up antimalarials due to the fear of COVID-19 Coronavirus, it is important to know the side effects of antimalarials and manage them. Antimalarials for COVID prophylaxis and especially self-prophylaxis is associated with serious side effects that may cause death and permanent disability.

Prior to the FDA and other experts’ decision, Trump pushed people to start taking antimalarials, Hydroxychloroquine and Chloroquine.

News of people who poisoned themselves with antimalarials are coming and Trump is to be blamed for this [Ref]. Trump should have left the decision to the FDA chief. Anyways, Trump is a “Political Doctor”.

I am making an effort to highlight the important side effects and contraindications of antimalarials and people who should avoid taking antimalarials (Chloroquine and Hydroxychloroquine) for self-protection without prior approval by a healthcare provider.

Who Should NOT take Antimalarials for COVID Prophylaxis?

Before listing the high-risk individuals who should avoid taking antimalarials for COVID prophylaxis, it is important to know that antimalarials are not 100% protective.

We do not know if they are even 50% protective. Furthermore, they may reduce the incidence of COVID-pneumonia or reduce the complications of COVID-pneumonia, they can not protect you from getting the infection.

However, since this is a desperate situation, some experts are promoting its use for COVID prophylaxis.

Another important point to note is that the dose for prophylaxis of COVID infection is different from COVID treatment.

Chloroquine Dose for COVID Prophylaxis: 500 mg of Chloroquine Phosphate (Two tablets) taken orally once a week with food. Hydroxychloroquine Dose for COVID Prophylaxis: 400 mg of Hydroxychloroquine (Two tablets of 200 mg HCQ) taken orally once a month with food.

At the above-recommended dose, the chances of getting the side-effects are very less. Still, if you fall in any of the following groups of patients, try to consult your healthcare provider prior to initiating its use.

Cardiac patients:

Both Chloroquine and Hydroxychloroquine can cause the following side effects in heart patients:

Cardiomyopathy: It may manifest as new-onset shortness of breath that may be difficult to differentiate from COVID-pneumonia!! However, it is more common in patients who are taking the drug for a prolonged duration and at higher doses.

Recommendations:

Any patient who develops new-onset shortness of breath, Bundle-branch blocks or Atrioventricular blocks should immediately discontinue the treatment.

QT-prolongation: QT-prolongation is a serious side effect of antimalarials that may even result after the intake of a single tablet. It may cause fatal ventricular arrhythmias that can cause sudden death of the patient. The most common arrhythmia associated with antimalarials is “Torsade de Pointes”.

Recommendations:

Any patient who is on medications that prolong the QT-interval (see a list of medicines below), have hypokalemia, hypomagnesemia, or bradycardia should avoid taking Chloroquine or hydroxychloroquine.

Eye Disease:

Eye disease in the form of retinal toxicity may occur in patients who are on long-term antimalarials or on higher doses (exceeding 5 mg/kg of Hydroxychloroquine and 2.3 mg/kg of Chloroquine). It may manifest as blurred vision, double vision, color changes, visuals field defects, night blindness, and irreversible macular degeneration.

Recommendations:

Any patient with a pre-existing eye disease (retinopathy), those with very low BMI (less than 19 Kg/m²), patients on Tamoxifen , and those with renal disease should avoid taking antimalarials for COVID prophylaxis.

Diabetics and patients at-risk of hypoglycemia:

Antimalarials can cause hypoglycemia (lower blood sugars) in diabetics and non-diabetics. Patients with Diabetes especially those on hypoglycemic drugs or insulin are at an increased risk of hypoglycemia.

Patients may develop palpitations, tremors, sweating, or may feel excessively hungry, and may become drowsy, develop seizures, or become unconscious.

Recommendations:

All patients should be asked to monitor their blood glucose and observe fo the symptoms of hypoglycemia during treatment and prophylaxis.

Patients at risk of hypoglycemia such as those with diabetes, gastrointestinal disorders (nausea, diarrhea, vomiting), adrenal insufficiency, hypothyroidism, renal or liver disease should take the drug with extreme caution.

Blood Disorders:

Antimalarials can cause severe blood-related side effects. These include agranulocytosis, aplastic anemia, neutropenia, pancytopenia, and thrombocytopenia. It should be taken with extreme caution in patients with G6PD deficiency.

Recommendations:

Patients who have an underlying blood disorder should take the drug with extreme caution.

Frequent CBC monitoring is essential.

Neuromuscular disorders:

Antimalarial drugs can precipitate neuromuscular weakness. It primarily manifests as a weakness of the proximal muscles.

Patients may note the difficulty in getting up from squatting position, combing hair, and climbing stairs.

Neuromuscular weakness usually develops in patients who are taking antimalarials on a long-term basis.

Recommendations:

Patients who have a neuromuscular disorder like myasthenia gravis, polymyositis, proximal myopathy due to an endocrine disorder such as Cushing’s syndrome and hypothyroidism, hereditary myopathy such as Duchenne, Becker, and limb-girdle muscular dystrophy, and patients on high doses of statins should take the drug with extreme caution and frequently check their muscle strength.

Other precautions:

Patients who are allergic to chloroquine or hydroxychloroquine should avoid taking them.

Patients with liver and renal disease should take these drugs with caution.

Patients with psoriasis, porphyria, seizures, hearing disorder and gastrointestinal disorders should take these drugs with caution.

List of Drugs that are associated with QT-interval prolongation :

Drug Category Examples Antibiotics azithromycin (especially important as it is used to treat patients with Coronavirus infection in combination with Antimalarials. See Treatment Guidelines)

Clarithromycin

Erythromycin

Roxithromycin

Metronidazole (with alcohol)

Moxifloxacin

Ciprofloxacin

Gatifloxacin

Grepafloxacin

Levofloxacin

Sparfloxacin Anesthetics Halothane

Propofol

Sevoflurane Antipsychotics Risperidone

Fluphenazine

Haloperidol

Clozapine

Thioridazine

Ziprasidone

Pimozide

Droperidol

Chlorpromazine

Chlorprothixene

Dronedarone Antiarrhythmics Disopyramide

Procainamide

Quinidine

Amiodarone

Sotalol

Dofetilide Antifungals Fluconazole (in cirrhosis)

ketoconazole Antidepressants Amitriptyline

Clomipramine

Imipramine

Dothiepin

Doxepin

Citalopram Antihistamines Terfenadine

Astemizole Antivirals Nelfinavir Antimalarials Chloroquine

Mefloquine

Hydroxychloroquine

Halofantrine Miscellaneous important drugs Cilostazol

Domperidone

Levosulpiride

Ondansetron

Terlipressin Others Probucol

Cisapride

Anagrelide

Arsenic trioxide

Methadone

For a more detailed list, click the link here: https://crediblemeds.org/pdftemp/pdf/CombinedList.pdf