All this talk of HCQ and Z paks being unsafe is comical to me. Ask any rheumatologist how many patients they have on HCQ for years for autoimmune diseases. It is one of the most commonly used drugs for lupus and RA. I have numerous pts who have been on it for over 5 years with no side effects. The risk of retinal toxicity is non-existent for people who have been on it less than 6 months.

Z paks are literally among the most prescribed drugs with every PCP putting their patients on it as drug of first choice for most URIs and UTIs. It is even the most common drug given to international travellers as prophylaxis for traveler's diarrhea-it has replaced cipro- and some even use it to treat acne because it stays in the system for about 1-2 weeks after stopping treatment.

Since both drugs can rarely prolong the QT interval on EKG which can cause aryrhmia, this might be a real risk in combining them and maybe reasonable with regards to the caution. I don't have any experience with this.