Methotrexate, ciclosporin and retinoid monitoring

01Purpose and principlesWhat the treatment does and how it fits into care.

The three medicines fill different dermatology roles. Methotrexate is a slower conventional systemic option for chronic inflammatory disease and is NICE first choice for many adults with systemic-treatment-eligible psoriasis. Ciclosporin is useful when rapid or short-term control is needed and is often chosen for an unstable severe flare, but cumulative kidney and blood-pressure harm limits duration. Acitretin is particularly useful in pustular and hyperkeratotic disease and when immunosuppression is undesirable, although reproductive constraints can outweigh its cutaneous benefit.

Monitoring begins with a baseline against which change can be interpreted. For methotrexate, renal decline increases exposure and can turn a stable weekly dose toxic; folate antagonists, dehydration, NSAIDs and some antibiotics further narrow safety. Ciclosporin causes reversible renal vasoconstriction early and structural damage with prolonged exposure, so a percentage creatinine change from the individual's baseline matters. Acitretin affects hepatocytes, lipids, mucocutaneous tissue and bone and can form the long-retained metabolite etretinate in the presence of alcohol.

Shared care works only when responsibility is explicit. Record the target disease, dose, weekly day if relevant, monitoring schedule, acceptable results, action thresholds and which clinician releases the next prescription. Ask about private or hospital supplies to prevent duplication. A normal panel does not exclude infection, pneumonitis, pregnancy or incorrect daily methotrexate administration, so symptom and medicine questioning accompanies every result review.

Key points

Methotrexate for inflammatory skin disease is taken once weekly on one named day, never daily; tablet strength, folic-acid day and monitoring owner must remain unambiguous.
Methotrexate suppresses folate-dependent nucleotide synthesis and immune proliferation; marrow, liver, lung and renal-clearance toxicity make trends as important as absolute thresholds.
Ciclosporin blocks calcineurin signalling and acts rapidly, but vasoconstrictive nephrotoxicity, hypertension, electrolyte disturbance, infection and interactions limit continuous use.
Acitretin normalises keratinocyte differentiation and is not conventionally immunosuppressive, but dryness, liver and lipid toxicity and exceptionally prolonged teratogenic risk dominate monitoring.
Baseline methotrexate assessment includes FBC, renal and liver function, hepatitis and HIV risk assessment, pregnancy status, vaccination, alcohol, lung history and interacting medicines.
Before ciclosporin, obtain at least two creatinine and blood-pressure measurements and assess potassium, magnesium, lipids, urate, infection, cancer and interacting CYP3A medicines.
Before acitretin, document liver, fasting lipids, glucose risk and pregnancy-prevention eligibility; where pregnancy is possible, prevention and testing continue for three years after the last dose.
Trimethoprim or co-trimoxazole with methotrexate can cause profound marrow toxicity, while macrolides, azoles, grapefruit and many other agents can raise ciclosporin exposure.
A creatinine rise above 30% from the patient's pretreatment baseline on ciclosporin is clinically important even if the laboratory value still lies inside its population reference range.
Do not renew from a normal latest result alone: falling neutrophils, rising transaminases, increasing creatinine or blood pressure and missed monitoring require response before the next supply.

02Indications, selection and cautionsWho may benefit, who needs urgent treatment and important alternatives.

Methotrexate marrow toxicityRed flag

Mouth ulcers, sore throat, fever, bruising and bleeding with falling counts can progress rapidly, especially after daily dosing, renal decline or trimethoprim exposure.

Methotrexate pneumonitis

New dry cough, fever, breathlessness, hypoxaemia and diffuse interstitial change requires immediate drug withdrawal while infection is excluded.

Ciclosporin renal toxicity

A progressive creatinine increase, falling eGFR, hypertension, hyperkalaemia or tremor indicates exposure-related toxicity even without symptoms.

Ciclosporin interaction toxicity

A new macrolide, azole, diltiazem, grapefruit product or other CYP3A inhibitor can precede abrupt renal, neurological or blood-pressure deterioration.

Acitretin mucocutaneous effect

Cheilitis, dry eyes, epistaxis, fragile skin and hair thinning are dose-related and common, while severe headache or visual change raises intracranial-hypertension concern.

Acitretin metabolic toxicity

Rising triglycerides, transaminases or glucose can be asymptomatic until pancreatitis or hepatitis develops, making scheduled laboratory surveillance essential.

Reproductive exposure

A missed period, contraception failure or planned conception during methotrexate or within three years after acitretin requires immediate specialist advice.

Red flags requiring action

Fever, mouth ulceration, sore throat, bruising, bleeding, new breathlessness, jaundice, severe headache, very high blood pressure, falling urine output, rising creatinine, severe abdominal pain, visual change, pregnancy or a dosing discrepancy must interrupt routine prescribing and trigger prompt assessment.

03Assessment before treatmentTests and checks that guide safe selection.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Methotrexate baseline panelFirst step
Why
Identify marrow, liver, renal, infection, lung and reproductive contraindications.
Interpretation and limitations
Obtain FBC, renal and liver profiles, hepatitis B and C and HIV testing by risk and policy, pregnancy testing when relevant and chest assessment when lung disease or symptoms justify it.
02
Methotrexate serial bloods
Why
Detect toxicity after initiation, dose change and during maintenance.
Interpretation and limitations
Dermatology commonly checks FBC, liver and renal function every one to two weeks until dose stability, then every two to three months, with shorter intervals for higher-risk patients.
03
Methotrexate action thresholds
Why
Standardise response to clinically important laboratory change.
Interpretation and limitations
Withhold and discuss WCC below 3.5, neutrophils below 1.6, platelets below 140 ×10^9/L, albumin below 30 g/L, MCV above 105 fL, AST or ALT above 100 U/L, creatinine rise above 30% or a new eGFR below 60, while also acting on concerning trends.
04
Ciclosporin renal and blood-pressure baseline
Why
Create an individual reference for nephrotoxicity and hypertension.
Interpretation and limitations
Use at least two pretreatment creatinine and blood-pressure readings and measure renal profile, potassium, magnesium, lipids, urate and liver function before treatment.
05
Ciclosporin treatment surveillance
Why
Identify early vasoconstrictive toxicity and interaction effects.
Interpretation and limitations
Check creatinine and blood pressure about every two weeks initially and after dose or interaction change, then at least monthly when stable; a sustained greater-than-30% creatinine rise prompts dose reduction or withdrawal.
06
Acitretin metabolic panel
Why
Monitor hepatic, lipid and glucose effects.
Interpretation and limitations
Measure liver tests and fasting lipids before treatment, after initiation and at specialist-defined intervals, with glucose monitoring when diabetes or metabolic risk exists; investigate severe triglyceride rise or abdominal pain urgently.
07
Acitretin pregnancy-prevention monitoring
Why
Prevent exposure during and long after treatment.
Interpretation and limitations
Use documented highly effective contraception and regular pregnancy testing before, during and for three years after treatment under the MHRA programme; no blood donation occurs during the same post-treatment period.

04Treatment approachPreparation, options, escalation and aftercare.

01First-line safe initiationBuild the baseline before the first doseFirst stepFirst lineA conventional systemic dermatology medicine has been selected.

1Confirm disease indication, previous therapy, infection and cancer history, vaccination, pregnancy plans, alcohol, comorbidity and every interacting prescription and non-prescription product.
2Obtain the medicine-specific baseline and agree exact dose, administration, laboratory interval, symptom actions and which clinician owns each result and prescription.
3Give a written medicine card: one named weekly day for methotrexate, blood-pressure and interaction precautions for ciclosporin, or pregnancy and alcohol restrictions for acitretin.

02Abnormal-result routeAct on direction as well as thresholdA count, transaminase, creatinine, eGFR, lipid or blood-pressure result changes during treatment.

1Compare with baseline and previous values, check dose timing, hydration, infection, alcohol and new medicines and repeat urgently when sampling error is plausible.
2Withhold treatment and contact the responsible specialist when a stop threshold, sustained 30% ciclosporin-creatinine rise or concerning trend is reached.
3Treat the complication, remove interactions and restart at a revised dose only after the cause, recovery target and tighter monitoring are documented.

03Serious infectionPause immunosuppression without losing disease controlA patient on methotrexate or ciclosporin develops systemic or invasive infection.

1Assess sepsis, obtain cultures without delaying antimicrobials and withhold methotrexate or ciclosporin while the prescribing specialist is contacted.
2Screen proposed anti-infectives for marrow, renal and CYP3A interactions, particularly trimethoprim with methotrexate and macrolides or azoles with ciclosporin.
3Restart only after clinical recovery and organ results are acceptable, balancing rebound of severe skin disease against recurrent infection risk.

04Reproductive safetyPlan before conception and act on exposurePregnancy is possible, desired or confirmed during a teratogenic-treatment window.

1AlternativeBefore initiation, document counselling, contraception and testing and select an alternative when the required prevention period is unacceptable.
2Stop methotrexate before planned maternal conception according to current specialist guidance and continue acitretin contraception and testing for three years after the final dose.
3For suspected pregnancy exposure, stop the contraindicated medicine and obtain urgent dermatology and fetal-medicine advice without presenting exposure as a predetermined fetal outcome.

05Regimens, contraindications and interactionsTreatment details and the circumstances that modify them.

Slower conventional systemic immunomodulator for chronic psoriasis and selected inflammatory dermatoses.

Methotrexate

For systemic-treatment-eligible psoriasis, NICE uses incremental initiation such as 5–10 mg orally once weekly, increasing to the lowest effective dose up to 25 mg once weekly; assess response after 3 months at target dose.

Never daily. Use one named weekday and one tablet strength, co-prescribe folic acid on another day, avoid pregnancy and trimethoprim or co-trimoxazole, adjust for renal function and monitor marrow, liver, lung and infection toxicity.

Reduces gastrointestinal, mucosal and hepatic adverse effects and supports continued safe low-dose methotrexate treatment.

Folic acid with methotrexate

Prescribe at least 5 mg orally once weekly on a day different from methotrexate; a specialist may increase the amount or number of non-methotrexate days for adverse effects.

Do not place routinely on the methotrexate day unless a specialist protocol says so, and do not confuse ordinary folic acid supplementation with folinic-acid rescue for overdose.

Rapid, usually time-limited systemic control when urgent improvement is needed or methotrexate is unsuitable.

Ciclosporin

For severe psoriasis, give 2.5–3 mg/kg/day orally in 2 divided doses; increase towards 5 mg/kg/day after 4 weeks for inadequate response, or sooner only when rapid disease control is necessary.

Monitor baseline-relative creatinine and blood pressure, renal profile, potassium, magnesium and interactions. Avoid grapefruit and live vaccines; continuous treatment beyond one year is exceptional and requires specialist justification.

Non-immunosuppressive oral retinoid for selected pustular, hyperkeratotic or severe psoriasis when other conventional options are unsuitable or ineffective.

Acitretin

Use specialist incremental oral dosing towards 25 mg once daily for psoriasis; increase to no more than 50 mg daily only when other treatment options are unavailable, and assess response by 4 months.

Highly teratogenic: pregnancy prevention, testing and no blood donation continue for 3 years after stopping where pregnancy is possible. Avoid alcohol during treatment and for 2 months after, tetracyclines and vitamin-A supplements; monitor liver and fasting lipids.

06Complications, monitoring and follow-upAdverse effects, response and longer-term review.

Before every repeat, verify methotrexate weekly day and tablet strength, ciclosporin dose and interacting medicines, or acitretin pregnancy-prevention status.
Plot blood-count, ALT or AST, albumin, creatinine, eGFR, blood pressure and lipid trends rather than viewing the latest result in isolation.
Increase monitoring after any dose change, acute illness, dehydration, renal decline, interacting medicine, abnormal result or transition between prescribers.
Ask directly about fever, mouth ulcers, bruising, cough, breathlessness, headache, tremor, urine output, jaundice, abdominal pain, visual change and pregnancy.
Document disease response with a reproducible skin and life-impact measure so toxicity is not accepted for a treatment that is not working.
Stop or switch when cumulative renal, hepatic, metabolic, reproductive or adherence burden outweighs control, and hand over an explicit post-treatment monitoring plan.

07Special situationsVariants, exceptions and circumstances that change the usual approach.

Baseline beats reference range

A creatinine still labelled normal can represent major ciclosporin toxicity when it has risen more than 30% from the person's pretreatment value.

Trends warn before thresholds

A steady neutrophil fall or transaminase rise may require action before a single result crosses the generic stop line.

One week is a safety system

A named methotrexate day, consistent tablet strength and separate folate day reduce fatal confusion across prescribing and dispensing transitions.

Alcohol prolongs retinoid risk

Ethanol can promote conversion of acitretin to longer-retained etretinate, supporting strict alcohol avoidance during and for two months after treatment.

Retinoid is not infection neutral

Acitretin is not conventionally immunosuppressive, but fissuring and barrier dryness can still complicate wounds and infection assessment.

Shared care needs an owner

A result seen by several services but acted on by none is less safe than a clearly assigned prescriber with a documented threshold plan.

08Common pitfallsFrequent interpretation and management errors.

01
Writing methotrexate daily instead of once weekly or mixing 2.5 mg and 10 mg tablets without a deliberate safety plan.
02
Prescribing trimethoprim for a urinary infection without reconciling methotrexate.
03
Judging ciclosporin renal safety against the laboratory range rather than the patient's pretreatment creatinine.
04
Starting clarithromycin or an azole without reviewing ciclosporin exposure and alternatives.
05
Treating normal latest bloods as permission to ignore fever, mouth ulcers or new breathlessness.
06
Ending acitretin contraception or blood-donation restrictions months rather than three years after stopping.
07
Ignoring alcohol, tetracycline and vitamin-A exposure during retinoid care.
08
Continuing a toxic medicine because no objective disease-response target was recorded.