Monitoring During Active Treatment
Physicians need to counsel patients on potential adverse effects of their medications. Because of its relatively safe profile among the systemic nonbiologic agents, apremilast requires the least monitoring during treatment. There is no required routine laboratory monitoring for patients using apremilast, though testing may be pursued at the clinician’s discretion. However, weight should be regularly measured in patients on apremilast. In a phase 3 clinical trial of patients with psoriasis, 12% of patients on apremilast experienced a 5% to 10% weight loss compared to 5% of patients on placebo.11,13 Thus, it is recommended that physicians consider discontinuing apremilast in patients with a weight loss of more than 5% from baseline, especially if it may lead to other unfavorable health effects. Because depression is reported among 1% of patients on apremilast, close monitoring for new or worsening symptoms of depression should be performed during treatment.11,13 To avoid common GI side effects, apremilast is initiated at 10 mg/d and is increased by 10 mg/d over the first 5 days to a final dose of 30 mg BID. Elderly patients in particular should be cautioned about the risk of dehydration associated with GI side effects. Patients with severe renal impairment (Cr clearance, <30 mL/min) should use apremilast at a dosage of 30 mg once daily.
For patients on methotrexate, laboratory monitoring is essential after each dose increase. It also is important for physicians to obtain regular blood work to assess for hematologic abnormalities and hepatoxicity. Patients with risk factors such as renal insufficiency, increased age, hypoalbuminemia, alcohol abuse and alcoholic liver disease, and methotrexate dosing errors, as well as those prone to drug-related interactions, must be monitored closely for pancytopenia.14,15 The protocol for screening for methotrexate-induced hepatotoxicity during treatment depends on patient risk factors. Risk factors for hepatoxicity include history of or current alcohol abuse, abnormal LFTs, personal or family history of liver disease, diabetes, obesity, use of other hepatotoxic drugs, and hyperlipidemia.16 In patients without blood work abnormalities, CBC and LFTs can be performed every 3 to 6 months. Patients with abnormally elevated LFTs require repeat blood work every 2 to 4 weeks. Persistent elevations in LFTs require further evaluation by a GI specialist. After a cumulative dose of 3.5 to 4 g, patients should receive a GI referral and further studies (such as vibration-controlled transient elastography or liver biopsy) to assess for liver fibrosis. Patients with signs of stage 3 liver fibrosis are recommended to discontinue methotrexate and switch to another medication for psoriasis. For patients with impaired renal function, periodic BUN and Cr monitoring are needed. Common adverse effects of methotrexate include diarrhea, nausea, and anorexia, which can be mitigated by taking methotrexate with food or lowering the dosage.8 Patients on methotrexate should be monitored for rare but potential risks of infection and reactivation of latent TB, hepatitis, and lymphoma. To reduce the incidence of methotrexate toxicity from drug interactions, a review of current medications at each follow-up visit is recommended.
Nephrotoxicity and hypertension are the most common adverse effects of cyclosporine. It is important to monitor BUN and Cr biweekly for the initial 3 months, then at monthly intervals if there are no persistent abnormalities. Patients also must receive monthly CBC, potassium and magnesium levels, uric acid levels, lipid panel, serum bilirubin, and LFTs to monitor for adverse effects.17 Physicians should obtain regular pregnancy tests in WOCP. Weekly monitoring of early-morning blood pressure is recommended for patients on cyclosporine to detect early cyclosporine-induced nephrotoxicity. Hypertension on 2 separate occasions warrants a reduction in cyclosporine dosage or an addition of a calcium channel blocker for blood pressure control. Dose reduction also should be performed in patients with an increase in Cr above baseline greater than 25%.17 If Cr level is persistently elevated or if blood pressure does not normalize to lower than 140/90 after dose reduction, cyclosporine should be immediately discontinued. Patients on cyclosporine for more than a year warrant an annual estimation of glomerular filtration rate because of irreversible kidney damage associated with long-term use. A systematic review of patients treated with cyclosporine for more than 2 years found that at least 50% of patients experienced a 30% increase in Cr above baseline.18
Patients taking acitretin should be monitored for hyperlipidemia, the most common laboratory abnormality seen in 25% to 50% of patients.19 Fasting lipid panel and LFTs should be performed monthly for the initial 3 months on acitretin, then at 3-month intervals. Lifestyle changes should be encouraged to reduce hyperlipidemia, and fibrates may be given to treat elevated triglyceride levels, the most common type of hyperlipidemia seen with acitretin. Acitretin-induced toxic hepatitis is a rare occurrence that warrants immediate discontinuation of the medication.20 Monthly pregnancy tests must be performed in WOCP.
Combination Therapy
For apremilast, there is anecdotal evidence supporting its use in conjunction with phototherapy or biologics in some cases, but no high-quality data.21 On the other hand, using combination therapy with other systemic therapies can reduce adverse effects and decrease the amount of medication needed to achieve psoriasis clearance. Methotrexate used with etanercept, for example, has been more effective than methotrexate monotherapy in treating psoriasis, which has been attributed to a methotrexate-mediated reduction in the production of antidrug antibodies.22,23
Methotrexate, cyclosporine, and acitretin have synergistic effects when used with phototherapy. Narrowband UVB (NB-UVB) phototherapy combined with methotrexate is more effective in clearing psoriasis than methotrexate or NB-UVB phototherapy alone. Similarly, acitretin and PUVA combination therapy is more effective than acitretin or PUVA phototherapy alone. Combination regimens of acitretin and broadband UVB phototherapy, acitretin and NB-UVB phototherapy, and acitretin and PUVA phototherapy also have been more effective than individual modalities alone. Combination therapy reduces the cumulative doses of both therapies and reduces the frequency and duration of phototherapy needed for psoriatic clearance.24 In acitretin combination therapy with UVB phototherapy, the recommended regimen is 2 weeks of acitretin monotherapy followed by UVB phototherapy. For patients with an inadequate response to UVB phototherapy, the UVB dose can be reduced by 30% to 50%, and acitretin 25 mg/d can be added to phototherapy treatment. Acitretin-UVB combination therapy has been shown to reduce the risk of UVB-induced erythema seen in UVB monotherapy. Similarly, the risk of squamous cell carcinoma is reduced in acitretin-PUVA combination therapy compared to PUVA monotherapy.25
The timing of phototherapy in combination with systemic nonbiologic agents is critical. Phototherapy used simultaneously with cyclosporine is contraindicated owing to increased risk of photocarcinogenesis, whereas phototherapy used in sequence with cyclosporine is well tolerated and effective. Furthermore, cyclosporine 3 mg/kg/d for 4 weeks followed by a rapid cyclosporine taper and initiation of NB-UVB phototherapy demonstrated resolution of psoriasis with fewer NB-UVB treatments and less UVB exposure than NB-UVB therapy alone.26
Final Thoughts
The FDA-approved systemic nonbiologic agents are accessible and effective treatment options for adults with widespread or inadequately controlled psoriasis. Selecting the ideal therapy requires careful consideration of medication toxicity, contraindications, monitoring requirements, and patient comorbidities. The AAD-NPF guidelines guide dermatologists in prescribing systemic nonbiologic treatments in adults with psoriasis. Utilizing these recommendations in combination with clinician judgment will help patients achieve safe and optimal psoriasis clearance.