PpxAid

• About
• Factors
• Interpretation
• Standard of Practice
• References

About

PpxAids are a decision aid tool that determine the optimal choice of prophylaxis against gout flares for a given patient who is starting urate-lowering therapy (ULT). For advice on whether or not a patient needs prophylaxis, use a Ppx.

Factors

PpxAid takes into account the following factors:

• Patient's age - NSAIDs are generally safe in younger patients, but should be used with caution in older patients. Age is also used to calculate kidney function when dosing colchicine.

• Patient's gender - Biological gender is used to calculate kidney function when dosing colchicine.

• Cardiovascular disease - NSAIDs are generally contraindicated in patients with cardiovascular disease. It's probably safe to use them for a limited, short-duration, but out of caution GoutHelper defaults to avoiding NSAIDs in patients with cardiovascular disease.

• Anticoagulation - NSAIDs can increase the risk of bleeding. Thus, anticoagulation is generally a contraindication to NSAID use.

• Bleed - NSAIDs can increase the risk of bleeding. Thus, a recent bleed or a history of a serious bleed is generally a contraindication to NSAID use.

• Gastric gypass - Patients who have had gastric bypass surgery are prone to developing ulcers at the site of their bypass. Thus, gastric bypass is generally a contraindication to NSAID use.

• Inflammatory bowel disease - There is some low-quality evidence that NSAIDs can worsen inflammatory bowel disease. Thus, inflammatory bowel disease is generally a contraindication to NSAID use.

• Chronic kidney disease - NSAIDs are generally contraindicated in patients with chronic kidney disease. Colchicine has to be dose-adjusted for patient's with early (under stage III) chronic kidney disease, but is contraindicated in patients with stage IV or V chronic kidney disease.

• Colchicine interactions - Colchicine has a long list of drug interactions, some of which are serious. Always double-check for interactions before prescribing colchicine.

• Diabetes - Steroids, such as prednisone or methylprednisolone, can raise blood sugar. They should be used with caution in patients with diabetes.

• Organ tranpslant - Organ transplants are complicated and patients who get them are often on a lot of carefully monitored medications. Adding new medications to the mix can be tricky. Always discuss with the patient's transplant team before prescribing new medications.

Interpretation

Given that all the prophylaxis treatments for gout are basically equally effective, PpxAid will provide what is generally considered the best treatment option in order of:

1. The least potential for harm to the patient
2. The cost and ease of access to the medication

Standard of Practice

Not all providers who manage gout use prophylaxis when initiating ULT. While this does not adhere to the ACR guidelines, this is probably OK. The risk of flares is highest in the first 3-6 months of ULT and then decreases over time. Prophylaxis is intended to reduce the burden of flares on the patient and to improve compliance with ULT, the thought being that fewer flares will make it more likely that the patient will continue to take their ULT. Alternative strategies in select patients, whereby the patient treats his or her flares early and aggressively, is also a reasonable strategy. The burden of more pills, extra and potentially confusing instructions about how to take what and when, and the potential for side effects from prophylaxis may outweigh the benefits of prophylaxis in some patients.

References

1. FitzGerald JD, Dalbeth N, Mikuls T, Brignardello-Petersen R, Guyatt G, Abeles AM, Gelber AC, Harrold LR, Khanna D, King C, Levy G, Libbey C, Mount D, Pillinger MH, Rosenthal A, Singh JA, Sims JE, Smith BJ, Wenger NS, Bae SS, Danve A, Khanna PP, Kim SC, Lenert A, Poon S, Qasim A, Sehra ST, Sharma TSK, Toprover M, Turgunbaev M, Zeng L, Zhang MA, Turner AS, Neogi T. 2020 American College of Rheumatology Guideline for the Management of Gout. Arthritis Care Res (Hoboken). 2020 Jun;72(6):744-760. doi: 10.1002/acr.24180. Epub 2020 May 11. Erratum in: Arthritis Care Res (Hoboken). 2020 Aug;72(8):1187. Erratum in: Arthritis Care Res (Hoboken). 2021 Mar;73(3):458. PMID: 32391934.