[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Other antineoplastics (differentiating agents, asparaginases, proteasome inhibitors)](https://durgical.com/en/pharmacology/classes/other-antineoplastics/) › Tretinoin

# Tretinoin

## Other antineoplastics (differentiating agents, asparaginases, proteasome inhibitors)?

Other antineoplastics (differentiating agents, asparaginases, proteasome inhibitors)

## High alert?

An error with this medicine can cause serious harm: double checks and protocols are used.

## Pregnancy: avoid?

Avoid in pregnancy. A potent teratogen (boxed warning): pregnancy must be excluded before and prevented during treatment and for a month after; breastfeeding is not advised.

All-trans retinoic acid taken by mouth for acute promyelocytic leukaemia: it makes the leukaemic cells mature. Watch for differentiation syndrome.

Updated Nov 1, 2026

Also called: all-trans retinoic acid (ATRA)

## Quick facts

**Group**
[Other antineoplastics (differentiating agents, asparaginases, proteasome inhibitors)](https://durgical.com/en/pharmacology/classes/other-antineoplastics/)

**Target**
Retinoic acid receptor α (RARα), part of the PML-RARα fusion in APL

**Used for**
Acute promyelocytic leukaemia

**Key effects**
Headache · Dry skin · Nausea

**Monitor**
Daily weight · White cell count · Coagulation tests

**ATC**
L01XF01

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Clinical What the labels mean

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

◎**Retinoic acid receptor α (RARα), part of the PML-RARα fusion in APL**Tretinoin

ⓘ The crystal shows the ligand-binding domain of human RARα holding retinoic acid, paired with an RXRα domain and a short coactivator peptide; the RXRα partner holds a different, blocking ligand.

**Target in 3D:** Retinoic acid receptor α (RARα), part of the PML-RARα fusion in APL. PDB structure 3A9E (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/3A9E) · Drag to rotate · pinch to zoom

In APL the t(15;17) translocation fuses PML to the retinoic acid receptor α. The PML-RARα protein binds retinoids poorly and keeps a repressor on the genes of myeloid maturation, so promyelocytes accumulate. At pharmacological levels tretinoin displaces the repressor, switches on the maturation program and promotes degradation of PML-RARα. Leukaemic promyelocytes mature into neutrophil-like cells, the bleeding tendency of APL improves, and normal blood formation returns.

- t(15;17) makes PML-RARα, which blocks maturation
- High-level tretinoin displaces the repressor
- PML-RARα is degraded; maturation genes switch on
- Promyelocytes mature; bleeding tendency improves

## Indications

- Acute promyelocytic leukaemia with t(15;17) or PML-RARα, to induce remission; usually combined with arsenic trioxide or an anthracycline. [Acute leukaemia (AML and ALL) →](https://durgical.com/en/conditions/acute-leukaemia/)

## Adverse effects

### Common

- Headache, fever, bone pain
- Dry skin, lips and mucous membranes
- Nausea, vomiting, abdominal pain
- Raised triglycerides and cholesterol
- Raised liver enzymes
- Rising white cell count

### Serious (rare, important)

- Differentiation syndrome: fever, breathlessness, weight gain, lung infiltrates, pleural or pericardial effusions, hypotension, kidney failure
- Severe birth defects (boxed warning)
- Raised intracranial pressure (pseudotumour cerebri), especially in children
- Venous and arterial clots in the first month
- Hepatotoxicity

## Contraindications

- Allergy to tretinoin or other retinoids

## Key interactions

**Strong CYP3A inhibitors (e.g. azole antifungals) and inducers**
Avoided: inhibitors raise tretinoin levels and toxicity (including high calcium); inducers lower its effect.

**Tetracyclines and other drugs that raise intracranial pressure**
Avoided because they add to the risk of pseudotumour cerebri.

**Antifibrinolytics (tranexamic acid, aminocaproic acid)**
Avoided because of the risk of thrombosis.

**Vitamin A supplements**
Avoided; they add to retinoid toxicity.

## What is monitored

- Daily weight, temperature, breathing and oxygen saturation in the first weeks (differentiation syndrome)
- White cell count
- Coagulation tests
- Fasting triglycerides and cholesterol
- Liver tests
- Pregnancy test before starting

## Administration and safety

- Oral capsules, swallowed whole; the oral leukaemia capsules are a different product from tretinoin creams and gels for acne.
- A negative pregnancy test and two effective contraceptive methods are required for women who can become pregnant.
- It may be started on a morphological diagnosis of APL while genetic confirmation is pending.
- At the first signs of differentiation syndrome, corticosteroids are started immediately as ordered.

## Pregnancy and breastfeeding

Avoid in pregnancy. A potent teratogen (boxed warning): pregnancy must be excluded before and prevented during treatment and for a month after; breastfeeding is not advised.

## Nursing care

- Weigh daily and check temperature, breathing and saturation; report fever, breathlessness or weight gain at once.
- Look for bleeding and follow coagulation results (APL causes coagulopathy).
- Ask about headache, vomiting or blurred vision (raised intracranial pressure).
- Teaching: two forms of contraception, no vitamin A supplements, and moisturisers for dry skin and lips.

## Pharmacokinetics

**Absorption**
Oral capsules; about half of the dose is absorbed.

**Distribution**
Highly bound to albumin.

**Metabolism**
Liver CYP enzymes (CYP3A4, CYP2C8) and glucuronidation; it induces its own metabolism, so levels fall within a week.

**Elimination**
Metabolites mainly in the urine, the rest in the faeces.

**Half-life**
Short: about half an hour to two hours.

## Memory aid

«ATRA matures APL»: it treats the t(15;17) leukaemia by forcing promyelocytes to grow up. Fever + breathlessness + weight gain = differentiation syndrome → steroids now.

## Test yourself

Think of the answer, then tap the question to see it.

## Which fusion protein does tretinoin act on in APL?

PML-RARα, produced by the t(15;17) translocation.

## Five days into tretinoin, a patient has fever, dyspnoea, weight gain and lung infiltrates. What is it, and what is done?

Differentiation syndrome; high-dose corticosteroids are started immediately with haemodynamic monitoring.

## Why is tranexamic acid avoided with tretinoin?

Because the combination increases the risk of thrombosis.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/tretinoin/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## What the labels mean

**High alert**
An error with this medicine can cause serious harm: double checks and protocols are used.

**Pregnancy: avoid**
Avoid in pregnancy. A potent teratogen (boxed warning): pregnancy must be excluded before and prevented during treatment and for a month after; breastfeeding is not advised.

## Connections

## Related drugs 1

- [Arsenic trioxide](https://durgical.com/en/pharmacology/arsenic-trioxide/)

## Related conditions 1

- [Acute leukaemia (AML and ALL)](https://durgical.com/en/conditions/acute-leukaemia/)

[← Back to the class: Other antineoplastics (differentiating agents, asparaginases, proteasome inhibitors)](https://durgical.com/en/pharmacology/classes/other-antineoplastics/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - TRETINOIN capsule](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=9c4ae9d9-c2a0-4995-a27a-e3f0f0284db9) (DailyMed (U.S. National Library of Medicine), 2026); [Tretinoin: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a608032.html) (MedlinePlus (U.S. National Library of Medicine), 2016); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L01XF01) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/pharmacology/tretinoin/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/tretinoin/