Tetracyclines

Question 1

MoA

Answer 1

Inhibits bacterial protein synthesis
Binds to ribosomal 30S subunit
Broad spectrum
Bacteriostatic

Question 2

Indications

Answer 2

LRTIs
Acne
Rosacea
Malaria
Chlamydia
MRSA

Question 3

Examples

Answer 3

Tetracycline
Oxytetracycline
Doxycycline
Lymecycline
Minocycline
Demeclocycline
Tigecycline

Question 4

Doxycycline

Answer 4

Malaria + Chlamydia
OD
Taken with food

Question 5

Minocycline

Answer 5

Broader spectrum
Rarely used

Question 6

Tigecycline

Answer 6

Antibiotic that is structurally related to tetracyclines

Question 7

Side effects

Answer 7

Angioedema
Diarrhoea
Hypersensitivity reactions
Photosensitivity reactions
Benign intracranial hypertension

Question 8

Benign intracranial hypertension

Answer 8

Headaches
Visual disturbances
STOP

Question 9

Contraindications

Answer 9

Children under 12
Pregnancy & BF
- Deposits in growing bone and teeth.
- Causes teeth discolouration + dental enamel (hypoplasia)

Question 10

Renal impairment

Answer 10

Avoid tetracyclines EXCEPT
- Doxycycline
- Minocycline

Question 11

Hepatic impairment

Answer 11

Hepatotoxic
Avoid or use with caution, ESPECIALLY with concomitant hepatotoxic drugs

Question 12

Photosensitivity

Answer 12

DD
- Doxycycline
- Demeclocycline
Avoid exposure to sunlight/sunlamps

Question 13

Decreased absorption

Answer 13

Do not take antacids, aluminium, calcium, iron, magnesium or zinc salts 2 hours before/after taking tetracyclines

Question 14

Avoid milk

Answer 14

DOT
- Demeclocycline
- Oxytetracycline
- Tetracycline

Question 15

Oesophageal irritation

Answer 15

DMT
- Doxycycline (caps)
- Minocycline (caps/tabs)
- Tetracycline (tabs)
Swallow whole with plenty of fluid during meals whilst sitting or standing upright

Question 16

Other contraindications + cautions

Answer 16

May increase muscle weakness in myasthenia gravis
May exacerbate systemic lupus erythematous