I’ve had multiple people send me links to people and/or “supposed experts” recommending the use of quinine to prevent coronavirus or COVID-19.  In my perspective, this is really bad advice and borders on malpractice.

Quinine was and still is used for the treatment of malaria. Yet, there are some significant reasons using quinine is, and should continue to be, limited.  Anyone recommending liberal daily use of quinine does not have any grasp of the potential for harm and death that can arise with the use of this substance.  I have seen quinine toxicity on a number of occasions in my 20 years of medical practice, and it ain’t pretty.

There is NO Evidence that Quinine Prevents COVID-19

There is absolutely no evidence that using quinine prevents infection from coronaviruses or COVID-19.  Quinine differs in its mechanism of action from hydroxychloroquine, one of the drugs currently under investigation for use with COVID-19.  Please, DO NOT confuse the two.

Even Small Amounts of Quinine Can be Deadly

Quinine use is the most common cause of immune-mediated drug induced thrombotic microangiopaty (DITMA), a life threatening condition caused by small-vessel platelet clots.  In a systematic review of all published reports describing drugs and other substances as a suspected cause of thrombotic microangiopathy (TMA), quinine was responsible for 34 of 104 cases in which there was definite evidence for a causal association (33 percent) [1].

The Oklahoma Thrombotic Thrombocytopenic Purpura-Hemolytic Uremic Syndrome (TTP-HUS) Registry found quinine-associated TMA in 19 of 509 patients (4 percent) referred for a possible TMA over a 25-year period and found quinine as the cause of DITMA in 20 of 23 patients (87 percent) for whom a drug could be implicated as having a definite or probable causal association with the TMA [2, 3].

A 2017 report describing the 19 individuals included in this registry found the following features [3]:

• All were white. This is distinctly different from Thrombotic Thrombocytopenic Purpura (TTP), in which approximately one-third are black (seven-fold higher than the reference population).
• Eighteen (95 percent) were women. This is greater than the increased frequency of women (75 percent) among patients with TTP.
• Eight (42 percent) had a prior history of quinine-related symptoms (nausea, vomiting, fever, chills, headache, confusion, ataxia).
• Thirteen (68 percent) could recall the precise timing between quinine ingestion and symptom onset (all ≤4 hours).
• Eighteen (95 percent) were caused by a quinine tablet; one was caused by quinine in tonic water of a vodka/tonic drink.
• Eighteen (95 percent) had evidence of quinine-dependent antiplatelet (or antineutrophil) antibodies.
• All had acute kidney injury; 17 of 18 required dialysis; three developed end-stage renal disease; and two underwent kidney transplantation.
• One died from complications of central venous catheter insertion. Of the remaining 18, eight died a median of nine years following diagnosis, five from cardiovascular disease or stroke that may have been related to the TMA.

Quinine is implicated in causing neutropenia (decrease of white blood cells in the immune system). When it occurs, neutropenia is often accompanied by other organ-system findings that may include thrombocytopenia (low platelet count), microangiopathic hemolytic anemia (the most common being DITMA referenced above), rash, acute kidney injury, fever/chills, and others.  The mechanism in many cases appears to be an acute, immune-mediated reaction to the drug.  Evidence to support these associations was evaluated in a 2016 systematic review of published reports, which found neutropenia in 24 (17 percent) of the 142 patients who had an immune-mediated quinine reaction.

Quinine + Sugar is A Perfect Storm

The problem that many physicians find is that quinine tablets may be borrowed from a friend or family member, or the exposure may occur from a beverage like Schwepps (eg, tonic water, bitter lemon).  And tonic water is loaded with sugar or high fructose corn syrup.   This high carbohydrate content, in combination with quinine is a perfect storm for kidney failure.

In the United States, the only available quinine tablet (Qualaquin) requires a prescription, and the only approved indication is for malaria treatment. This restricted availability of quinine tablets may explain why we have not seen a patient with quinine-induced TMA since 2009 [3]. There are also several over-the-counter tablets and herbal remedies for leg cramps available in the United States that may contain quinine, and quinine tablets can be purchased over-the-counter in Canada and other countries. Quinine may also be added to drugs of abuse such as cocaine.

Just One Dose of Quinine Can Be A Trigger

Importantly, TMA from quinine can be triggered either by a single ingestion (eg, one quinine tablet, one quinine-containing beverage) occurring many months or years after a previous exposure, up to 10 years in our experience. This is because the drug-dependent antibodies can persist for many years, but they cannot react with target cells in the absence of the drug. Acute immune-mediated tissue damage can occur within hours of re-exposure. It is not known whether the homeopathic doses of quinine present in remedies for leg cramps in the United States can trigger TMA, but in principle, immune-mediated DITMA can occur with extremely low levels of re-exposure.

Chronic kidney disease is common following quinine-induced TMA [3].

So, please, don’t follow bad advice about using quinine from people who have no concept of what these drugs can really do.

Please see my Coronavirus Page for information and recommendations on prevention and treatment.

References:

1. Al-Nouri ZL, Reese JA, Terrell DR, et al. Drug-induced thrombotic microangiopathy: a systematic review of published reports. Blood 2015; 125:616.
2. Reese JA, Bougie DW, Curtis BR, et al. Drug-induced thrombotic microangiopathy: Experience of the Oklahoma Registry and the Blood Center of Wisconsin. Am J Hematol 2015; 90:406.
3. Page EE, Little DJ, Vesely SK, George JN. Quinine-Induced Thrombotic Microangiopathy: A Report of 19 Patients. Am J Kidney Dis 2017; 70:686.