# ATC Classification System

The Anatomical Therapeutic Chemical (ATC) classification system is used in Sweden to categorize medications.

## Main Groups (1st Level)

| Code | Group | Swedish |
|------|-------|---------|
| A | Alimentary tract and metabolism | Matsmältningsorgan och ämnesomsättning |
| B | Blood and blood forming organs | Blod och blodbildande organ |
| C | Cardiovascular system | Hjärta och kretslopp |
| D | Dermatologicals | Hudsjukdomar |
| G | Genito-urinary system and sex hormones | Urin- och könsorgan samt könshormoner |
| H | Systemic hormonal preparations | Hormoner, systemiska |
| J | Antiinfectives for systemic use | Infektionssjukdomar |
| L | Antineoplastic and immunomodulating agents | Cancer och immunmodulerande medel |
| M | Musculo-skeletal system | Rörelseapparaten |
| N | Nervous system | Nervsystemet |
| P | Antiparasitic products | Antiparasitära medel |
| R | Respiratory system | Andningsorgan |
| S | Sensory organs | Ögon och öron |
| V | Various | Övrigt |

## Common Subgroups

### N - Nervous System
- **N02** - Analgesics (smärtstillande)
  - N02BE01 - Paracetamol
  - N02BA01 - Acetylsalicylic acid
- **N05** - Psycholeptics (lugnande)
  - N05BA - Benzodiazepine derivatives
  - N05CF - Benzodiazepine related drugs
- **N06** - Psychoanaleptics (antidepressiva)
  - N06AB - SSRIs

### C - Cardiovascular
- **C03** - Diuretics (vätskedrivande)
- **C07** - Beta blocking agents
- **C09** - Agents acting on renin-angiotensin system
- **C10** - Lipid modifying agents (statins)

### A - Alimentary
- **A02** - Drugs for acid related disorders
  - A02BC - Proton pump inhibitors
- **A10** - Drugs used in diabetes
  - A10BA - Biguanides (Metformin)

### R - Respiratory
- **R03** - Drugs for obstructive airway diseases
  - R03AC - Beta-2 agonists (Ventoline)
  - R03BA - Glucocorticoids (Pulmicort)

## Using ATC Codes

When searching FASS or Läkemedelsverket, you can use ATC codes to:
1. Find all medications in a therapeutic group
2. Identify equivalent medications (same ATC = similar action)
3. Understand medication classification

## Swedish Resources

- **FASS**: https://www.fass.se - Search by ATC code
- **Läkemedelsverket**: https://www.lakemedelsverket.se - Official registry
- **Janusmed**: https://janusmed.se - Interactions by ATC