Systemic Medications for the Dermatology Toolbox: Potassium Iodide Handout for Key Points

Transcription

1 Systemic Medications for the Dermatology Toolbox: Potassium Iodide Handout for Key Points Taraneh Paravar, MD Assistant Professor Department of Dermatology, UC San Diego March 3, 2017

2 DISCLOSURE OF RELATIONSHIPS WITH INDUSTRY Taraneh Paravar, MD F026 Systemic Medications for the Dermatology Toolbox DISCLOSURES I do not have any relevant relationships with industry. I have no conflicts of interest.

3 Objectives } Discuss the mechanism of action of potassium iodide } Apply recommendations concerning appropriate laboratory evaluations and monitoring of patients on potassium iodide } Review appropriate dosing

4 Potassium Iodide

5 Potassium Iodide (KI) Iodine was first discovered in seaweed in early 1800s Soon after was used to treat thyroid disorders and eventually other diseases: syphilis, eczema, and psoriasis Use outside of dermatology Blocking of absorption of radioactive iodine by thyroid in cases of nuclear accidents ( Used off-label in thyroidectomy preparation, thyrotoxic crisis, thyroid gland protection during radiopharmaceutical use Expectorant Sterling et al, JAAD 2000.

6 Dermatologic Uses } Reported dermatologic uses for potassium iodide (none FDA approved) } Panniculitis } Erythema nodosum } Nodular vasculitis } Subacute nodular migratory panniculitis } Neutrophilic dermatoses } Pyoderma gangrenosum } Sweet s syndrome } Infections } Sporotrichosis (fixed cutaneous and lymphocutaneous) } Miscellaneous } Behcet s syndrome } Erythema multiforme } Wegener s granulomatosis Adapted from Sterling et al, JAAD 2000.

7 Mechanism of Action } Mechanism of action (MOA) } Exact MOA in dermatologic disease is not known, but most effective in neutrophil predominant diseases

8 Caution } Contraindications } Absolute } Iodine sensitivity } Use with caution in } Hypothyroidism or any thyroid disease, cardiac disease, renal insufficiency, Addison s disease, hyperkalemia, hypocomplementemic vasculitis, myotonia congenita, tuberculosis, or patients with an impaired immune system } Pregnancy Category } Category D Potassium Iodide Prescribing Information 2015, Sterling et al, JAAD. 2000, Costa et al, An Bras Dermatol 2013

9 Adverse Effects } Common } GI } Skin rash, salivary gland swelling/tenderness } Iodism/chronic iodine poisoning (with prolonged use) } Hypersensitivity } Cutaneous: acneiform, dermatitic, vasculitic } May aggravate dermatitis herpetiformis, vasculitis, PAN, pustular psoriasis, BP } Acneiform eruptions } Iododerma } Potassium toxicity } Miscellaneous } Pulmonary edema, heart failure, death } Prolonged fever Potassium Iodide Prescribing Information 2015, Sterling et al, jaad, 2000, Hassan et al, Indian J Dermatol Venereol Leprol. 2012

10 Adverse Effects } Effect on thyroid metabolism } Iodine is essential for the production of the thyroid hormones T3 and T4 } Excess iodine leads to Wolff-Chaikoff effect (WCE): inhibition of hormone synthesis induced by large quantities of iodine } Autoregulation allows escape from WCE and the maintenance of a euthyroid state Potassium Iodide Prescribing Information 2015, Sterling et al, JAAD. 2000, Costa et al, An Bras Dermatol 2013, Heymann et al, JAAD 2000

11 Formulation } Often administered in saturated solution (SSKI) } Made by adding KI to hot purified water, using sodium thiosulfate as a preservative } 1000 mg/ml } Supplied in 30 ml and 237 ml bottles } Calibrated dropper marked to deliver 0.3 ml (300 mg) and 0.6 ml (600 mg) Sterling et al, JAAD 2000, Hassan et al, Indian J Dermatol Venereol Leprol 2012

12 Dosing } Inflammatory dermatoses } 300 mg (about 6 drops of SSKI) TID followed by weekly increases if needed } Can try daily increases of a drop every time the medicine is taken until the target dose is reached } Can start at 150 mg TID to mitigate adverse effects Sterling et al, JAAD 2000

13 Medication Interactions } Risk of hyperkalemia and potassium toxicity } Risk of hypothyroidism Potassium Iodide Prescribing Information 2015, Sterling et al, BJD 2000

14 Monitoring Guidelines } Baseline } History: personal or family history of thyroid disease, medication history including those that could affect thyroid function or cause increases in potassium level } For concern about underlying thyroid disease, recommend TSH, T4, antithyroglobulin, and antimicrosomal antibodies } otherwise not indicated, but I check baseline TSH for comparison } Follow-up } At one month, check TSH to assess for iodide-induced hypothyroidism } Consider checking TSH yearly Sterling et al, JAAD 2000

15 Monitoring Guidelines } Management of Adverse Reactions } To minimize GI effects } Avoid rapid dose increases, take the medicine after meals, with the intake of juice or milk } For iodism } D/c KI and give abundant fluids to eliminate iodide } Effects on thyroid } Mild Adjust KI dose } If iodide-induced hypothyroidism is detected d/c KI Ramirez et al Mycoses 2014, Jubiz et al J Clin Endocrinol Metab 1977, Sterling et al JAAD 2000, Hassan et al Indian J Dermatol Venereol Leprol 2012

16 References } Potassium Iodide Upsher-Smith Laboratories Prescribing Information 2015 } Sterling JB, Heymann WR. Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications. J Am Acad Dermatol Oct;43(4): } Hassan I, Keen A. Potassium iodide in dermatology. Indian J Dermatol Venereol Leprol May-Jun;78(3): } Costa RO, Macedo PM, Carvalhal A, Bernardes-Engemann AR. Use of potassium iodide in dermatology: updates on an old drug. An Bras Dermatol May-Jun;88(3): } Honma K, Saga K, Onodera H, Takahashi M. Potassium iodide inhibits neutrophil chemotaxis. Acta Derm Venereol. 1990;70(3): } Miyachi Y, Niwa Y. Effects of potassium iodide, colchicine and dapsone on the generation of polymorphonuclear leukocyte-derived oxygen intermediates. Br J Dermatol Aug;107(2):

17 References } Jubiz W, Carlile S, Lagerquist LD. Serum thyrotropin and thyroid hormone levels in humans receiving chronic potassium iodide. J Clin Endocrinol Metab.1977 Feb;44(2): } Heymann WR. Potassium iodide and the wolff-chaikoff effect: relevance for the dermatologist. J Am Acad Dermatol Mar; 42(3): } Leung AM, Braverman LE. Consequences of excess iodine. Nat Rev Endocrinol Mar;10(3): } Eng PH, Cardona GR, Fang SL, Previti M, Alex S, Carrasco N, Chin WW, Braverman LE. Escape from the acute Wolff-Chaikoff effect is associated with a decrease in thyroid sodium/iodide symporter messenger ribonucleic acid and protein. Endocrinology Aug; 140(8): } Ramírez Soto MC. Effects of potassium iodide in concentrations of TSH, tt3 and tt4 in serum of subjects with sporotrichosis. Mycoses Aug;57(8):460-5.

18 References } Honma K, Saga K, Onodera H, Takahashi M. Potassium iodide inhibits neutrophil chemotaxis. Acta Derm Venereol 1990; 70: } Schulz EJ, Whiting DA. Treatment of erythema nodosum and nodular vasculitis with potassium iodide. Br J Dermatol Jan;94(1):75-8. } Eng PH, Cardona GR, Fang SL, Previti M, Alex S, Carrasco N, et al. Escape from the acute Wolff-Chaikoff effect is associated with a decrease in thyroid sodium/iodide symporter messen- ger ribonucleic acid and protein. Endocrinology 1999;140: