[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antimetabolites](https://durgical.com/en/pharmacology/classes/antimetabolites/) › Gemcitabine

# Gemcitabine

## Antimetabolites?

Antimetabolites

## High alert?

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

A cytidine analogue with two fluorine atoms that blocks ribonucleotide reductase and ends DNA chains. Used in pancreatic, lung, bladder and ovarian cancer.

Updated Nov 1, 2026

## Quick facts

**Group**
[Antimetabolites](https://durgical.com/en/pharmacology/classes/antimetabolites/)

**Target**
Ribonucleotide reductase (inhibited by gemcitabine diphosphate) and DNA synthesis

**Used for**
Pancreatic cancer · Non-small cell lung cancer

**Key effects**
Myelosuppression · Flu-like symptoms · Oedema

**Monitor**
Complete blood count before each dose · Liver tests

**ATC**
L01BC05

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

Inside the cell nucleoside kinases phosphorylate gemcitabine to its diphosphate and triphosphate. The diphosphate inhibits ribonucleotide reductase, so the pool of deoxynucleotides (especially dCTP) falls. The triphosphate then competes more easily with dCTP and is built into DNA, where it ends the strand in a way that resists repair. Cells are blocked at the G1/S boundary.

- Kinases convert gemcitabine to its diphosphate and triphosphate
- The diphosphate blocks ribonucleotide reductase: dCTP falls
- The triphosphate enters DNA and ends the strand
- Cells stall at the G1/S boundary

## Indications

- Pancreatic cancer (first-line, advanced). [Pancreatic cancer →](https://durgical.com/en/conditions/pancreatic-cancer/)
- Non-small cell lung cancer, with cisplatin. [Lung cancer →](https://durgical.com/en/conditions/lung-cancer/)
- Advanced ovarian cancer, with carboplatin. [Ovarian cancer →](https://durgical.com/en/conditions/ovarian-cancer/)
- Metastatic breast cancer, with paclitaxel. [Breast cancer →](https://durgical.com/en/conditions/breast-cancer/)
- Bladder cancer, in combination regimens. [Bladder cancer →](https://durgical.com/en/conditions/bladder-cancer/)

## Adverse effects

### Common

- Myelosuppression (neutropenia, thrombocytopenia, anaemia)
- Flu-like symptoms: fever, chills, muscle aches, headache
- Oedema, rash
- Nausea, vomiting, raised liver enzymes

### Serious (rare, important)

- Pulmonary toxicity (pneumonitis, fibrosis, capillary leak) and respiratory failure
- Haemolytic uraemic syndrome
- Severe cutaneous reactions; liver toxicity
- Posterior reversible encephalopathy syndrome; worse radiation injury when given with radiotherapy

## Contraindications

- Known hypersensitivity to gemcitabine (including anaphylaxis)

## Key interactions

**Radiotherapy**
Gemcitabine is a radiosensitiser: severe tissue injury when given together or close in time.

**Other myelosuppressive chemotherapy (cisplatin, carboplatin, paclitaxel)**
Deeper cytopenias, especially thrombocytopenia.

## What is monitored

- Complete blood count before each dose
- Kidney function, urine and signs of haemolysis (haemolytic uraemic syndrome)
- Liver tests
- Breathing: new cough or breathlessness

## Administration and safety

- The infusion time and weekly schedule are kept as specified: longer infusions or more frequent doses are more toxic.
- Hazardous drug: chemotherapy handling precautions.
- Blood counts are checked before each dose; doses are held or reduced for severe myelosuppression.

## Pregnancy and breastfeeding

Can cause fetal harm; effective contraception is advised for women and men.

## Nursing care

- Check counts and creatinine before each dose.
- Teach that fever and aches after the infusion are common but that fever with chills during neutropenia is an emergency.
- Report new breathlessness, swelling, dark urine or reduced urine output.
- Check skin in any area that has received radiotherapy.

## Pharmacokinetics

**Absorption**
Intravenous infusion over a fixed, short time (longer infusions increase toxicity).

**Metabolism**
Rapidly deaminated by cytidine deaminase to an inactive uridine metabolite.

**Elimination**
Mainly in the urine as the inactive metabolite.

**Half-life**
Short for the parent drug; longer with long infusions.

## Memory aid

«GEMcitabine is a GEM that hides in DNA»: it ends DNA strands and blocks ribonucleotide reductase; pancreas, lung, bladder, ovary. Watch lungs and HUS.

## Test yourself

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

## Which two actions explain gemcitabine's effect?

Its diphosphate inhibits ribonucleotide reductase, and its triphosphate is built into DNA and ends the strand.

## Which cancer made gemcitabine famous as a single agent?

Pancreatic cancer.

## Which kidney syndrome can gemcitabine cause?

Haemolytic uraemic syndrome.

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

[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.

## Connections

## Related drugs 3

- [Cytarabine](https://durgical.com/en/pharmacology/cytarabine/)
- [Cisplatin](https://durgical.com/en/pharmacology/cisplatin/)
- [Carboplatin](https://durgical.com/en/pharmacology/carboplatin/)

## Related conditions 5

- [Pancreatic cancer](https://durgical.com/en/conditions/pancreatic-cancer/)
- [Lung cancer](https://durgical.com/en/conditions/lung-cancer/)
- [Ovarian cancer](https://durgical.com/en/conditions/ovarian-cancer/)
- [Breast cancer](https://durgical.com/en/conditions/breast-cancer/)
- [Bladder cancer](https://durgical.com/en/conditions/bladder-cancer/)

[← Back to the class: Antimetabolites](https://durgical.com/en/pharmacology/classes/antimetabolites/)

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 - GEMCITABINE injection, solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=e18ed1cb-7dd0-4001-bfda-17d1f4587fb8) (DailyMed (U.S. National Library of Medicine), 2026); [Gemcitabine Injection: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a696019.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=L01BC05) (WHO Collaborating Centre for Drug Statistics Methodology, 2026).

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Representative model, for educational purposes only.

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