Clindamycin, linezolid, trimethoprim, chloramphenicol

Question 1

How does clindamycin work ?

Answer 1

inhibits protein synthesis

Question 2

Clindamycin is ….. spectrum and bacter…..?

Answer 2

Narrow-spectrum and bacteriostatic. Clindamycin is active against Gram-positive cocci, including streptococci and penicillin-resistant staphylococci, and also against many anaerobes, especially Bacteroides fragilis. It is well concentrated in bone.

Question 3

What is patient advice regarding clindamycin ?

Answer 3

should be advised to discontinue and contact a doctor immediately if severe, prolonged or bloody diarrhoea develops.

Question 4

What factors increase the risk of C. difficile infection ?

Answer 4

increased age, history of C. difficile infection, exposure to other cases, concomitant use of a proton pump inhibitor or other acid-suppressing drug, and underlying morbidity (such as abdominal surgery, chronic renal disease, inflammatory bowel disease, and immunosuppression).

Question 5

Which antibiotics are frequently associated with C.difficile infection ?

Answer 5

clindamycin, cephalosporins (especially third and fourth generation), fluoroquinolones, and broad-spectrum penicillins.

Question 6

What are the monitoring parameters with clindamycin ?

Answer 6

Monitor liver and renal function if treatment exceeds 10 days.

Question 7

Young women has been prescribed Dalacin (clindamycin ) cream for vaginal use, what advise should you give regarding contraception ?

Answer 7

Damages latex condoms and diaphragms: with vaginal use

Question 8

How does linezolid and against with type of bacteria it works against ?

Answer 8

• inhibits protein synthesis
• only active against gramp positive bacteria; MRSA and anaerobes
• narrow spectrum/bacteriostatic

Question 9

If a patient has MRSA (super bug) infection and is intolerant to vancomycin, what would be the alternative ?

Answer 9

Linezolid

Question 10

What are the two important side effects of linezolid ?

Answer 10

optic neuropathy: especially if treatment is longer than 28 days,patients experiencing new visual symptoms (regardless of treatment duration) should be evaluated promptly.
Blood disorders: thrombocytopenia, anaemia, leucopenia, and pancytopenia

Question 11

What patient counselling should you provide to people on linezolid ?

Answer 11

• report symptoms of visual impairment (including blurred vision, visual field defect, changes in visual acuity and colour vision) immediately.
• visual function should be monitored regularly if treatment is required for longer than 28 days.
• avoid consuming large amounts of tyramine-rich foods (such as mature cheese, salami, pickled herring, Bovril®, Oxo®, Marmite® or any similar meat or yeast extract or fermented soya bean extract, and some beers, lagers or wines).

Question 12

It is recommended when taking linezolid that full blood counts should be monitored weekly. Close monitoring is recommended in which patient groups ?

Answer 12

• receive treatment for more than 10–14 days;
• have pre-existing myelosuppression;
• are receiving drugs that may have adverse effects on haemoglobin, blood counts, or platelet function;
• have severe renal impairment.

Question 13

Which drugs when given with linezolid ( reversible MAOI) can lead to hypertensive crisis ?

Answer 13

SSRIs, TCA's, MAOIs ( wait two weeks after stopping)
Pseudoephedrine
dopaminergics
Opioids
5-HT agonists
Buspirone
Pethidine

Question 14

What type of antibiotic is trimethoprim and how does it work ?

Answer 14

Narrow spectrum, bactericidal

Inhibits DNA synthesis

Question 15

What are the side effects of trimethoprim ?

Answer 15

Anti-folate
Blood dyscrasias with long-term use
Hyperkalaemia

Question 16

What counselling advise should you provide to people who take trimethoprim long-term ?

Answer 16

should be told how to recognise signs of blood disorders and advised to seek immediate medical attention if symptoms such as fever, sore throat, rash, mouth ulcers, purpura, bruising or bleeding develop.

Question 17

With long-term use of trimethoprim what monitoring you would recommend ?

Answer 17

Blood counts with long term use and those with or at risk of folate deficiency
Serum electrolytes: hyperkalaemia
Renal function

Question 18

What are the restrictions on the use of co-trimoxazole?

Answer 18

licensed for the prophylaxis and treatment of Pneumocystis jirovecii (Pneumocystis carinii) pneumonia and toxoplasmosis; it is also licensed for the treatment of nocardiosis.

Question 19

What are the rare but serious side effects associated with the use of co-trimoxazole ?

Answer 19

blood disorders (including leucopenia, thrombocytopenia, megaloblastic anaemia, eosinophilia) or rash (including Stevens-Johnson syndrome or toxic epidermal necrolysis) develop.

Question 20

How does chloramphenicol work ?

Answer 20

Inhibits protein synthesis

Broad-spectrum, bacteriostatic

Question 21

Why should chloramphenicol be avoided in the third trimester?

Answer 21

grey baby syndrome

Question 22

Why is chloramphenicol reserved only for life threatening infections ?

Answer 22

can cause blood dyscrasias

Question 23

How should patient use chloramphenicol eye drops for bacterial conjunctivitis ?

Answer 23

One drop to be instilled into the infected eye every two hours for the first 48 hours, and then every 4 hours thereafter. To be used during waking hours only.