Table 1.

Current medications used in Covid-19 infection and potential side effects in cardiomyopathies (CMP) and ion channel diseases (ICD)

DRUG	SIDE EFFECTS	USE in CMP and ICD
Hydroxychloroquine^a	QT prolongation (drug effect plus CYP3A4 inhibition)	Potentially harmful in LQTs, HCM or other CMPs associated with LQT, acquired QT status Caution in: hypokaliemia status, severe hypoglicemia, renal or epatic failure; digoxin, antiepilectics or ciclosporin therapy; patients with G6PDH and porfiria
Azitromicin^a	QT prolongation (drug effect plus mild CYP3A4 inhibition)	Potentially harmful in LQTs, HCM or other structural disease associated with LQT, acquired QT status
Ritonavir	QT prolongation (CYP3A4 inhibition) Bradyarrhythmias/AV blocks Hypertension, angioedema, maculopapular rash, respiratory tract infection, peripheral neuropathy, hypercholesterolemia, hypertriglyceridemia, increased glucose, increased uric acid, increased transaminases and creatine kinase, decreased CrCl, neutropenia, anemia Rare: ketoacidosis, insulin resistance, anorexia, hyperlactatemia, rhabdomyolysis	Potentially harmful in LQTs, HCM or other structural disease associated with LQT, acquired QT status Caution in patients with congenital, inherited (i.e. SCN5A), or structural (i.e. Lamin A/C, desmin, mitchocondrial) AV blocks Caution in patients with previous renal and hepatic diseases and/or previous peripheral neuropathy (i.e. Amyloidosis, Fabry disease), hypertension, familial hypercolesterolemia, uncompensated DM, mitochondrial or metabolic disorders, syndromes associated with anemia or neutropenia (i.e. Barth synfrome) Caution in patients taking sildenafil (i.e. pulmonary hypertension), sinvastatin, amiodaron, midazolam
Lopinavir	QT prolongation (CYP3A4 inhibition) Bradyarrhythmias/AV blocks Hypertension, angioedema, maculopapular rash, respiratory tract infection, peripheral neuropathy, hypercholesterolemia, hypertriglyceridemia, increased glucose, increased uric acid, increased transaminases and creatine kinase, decreased CrCl, neutropenia, anemia Rare: ketoacidosis, insulin resistance, anorexia, hyperlactatemia, rhabdomyolysis	Potentially harmful in LQTs, HCM or other structural disease associated with LQT, acquired QT status Caution in patients with congenital, inherited (i.e. SCN5A), or structural (i.e. Lamin A/C, desmin, mitchocondrial) AV blocks Caution in patients with previous renal and hepatic diseases and/or previous peripheral neuropathy (i.e. Amyloidosis, Fabry disease), hypertension, familial hypercolesterolemia, uncompensated DM, mitochondrial or metabolic disorders, syndromes associated with anemia or neutropenia (i.e. Barth synfrome) Caution in patients taking sildenafil (i.e. pulmonary hypertension), sinvastatin, amiodaron, midazolam
Remdesivir	No definite effect on cardiac electrical activity	Liver enzyme increase
Tocilizumab	No definite effect on cardiac electrical activity Drug idiosyncrasy, hypertension, hypercolesterolemia, respiratory tract or other infections, increased transaminase, reduced CrCl,	Caution in patients with previous renal and hepatic diseases, hypertension, familial hypercolesterolemia Caution in patients taking other immunosoppressive drugs (i.e. cortisone, ciclosporin), simvastatin/atorvastatin, amlodipin, teofillin, warfarin, temazepam
Low molecular weight Eparin	No definite effect on cardiac electrical activity Uncontrolled bleeding Heparin induced thrombocytopenia Elevated liver enzymes	Caution in patients with splenomegaly status (i.e. Gaucher disease, amyloidosis, sarcoidosis) Caution in patients with previous thrombocytopenia or coagulation factors deficits (i.e. Rasopathies: Noonan syndrome) Caution in patients with severe renal and hepatic diseases Caution in patients taking high dose diuretics, captopril, abciximab, clopidogrel, digoxin

^aIn absence of clear benefit and safety data from well designed, randomized, controlled clinical trials, the WHO and many national authorities have issued specific warnings for the use of hydroxychloroquine, particularly in association with azitromicin (https://www.who.int/emergencies/diseases/novel-coronavirus-2019/coronavirus-disease-answers?query=hydroxychloroquine)