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Drug monitoring has 2 sections.

1. Those drugs we have complete control of in GP. These are generally cheap but levels etc need monitoring.
2. Those drugs which are generally initiated by specialists and/or are expensive. Generally these have side effects which need monitoring. The info below is intended to be brief only and details our follow up policy. The full protocols can be found in the shared care folder.

• Audit

Follow up is as indicated. Phlebotomist responsible for running audit. 4 patient searches have been set up as regular searches. Dates need shifting.

1. Patients on diuretics and ACE inhibitors who have not had UE done in last 1y. This list of patients should receive a computer generated letter asking them to come in for UE.
2. Patients on thyroxine who have not had TSH done in last 1y. This list of patients should receive a computer generated letter asking them to come in for TSH.
3. A list of all patients on the "annual" recall drugs (not inc 1&2). Phlebotomist to manually go through this list and call patients by letter.
4. A list of all patients on the "6 monthly" recall drugs (not inc 1&2). Phlebotomist to manually go through this list and call patients by letter.

We will try this method initially. It is possible to partially automate 3&4, but I feel there will be less errors and for the small number of patients involved, I believe the work load will not be that more. The system is open to review.

• WARFARIN

Protocol. See the local shared care protocol for further details. New anticoagulation patients should have a relevant diagnosis entered on the system. Then one of 4 codes to be entered as an active problem –

On warfarin 2.5 Longterm
On warfarin 2.5 Time Nos
On warfarin 3.5 Longterm
On warfarin 3.5 Time Nos

2.5 and 3.5 refers to the desired INR level – 2.5 (2-3), 3.5 (3-4).
Longterm means for life.

Time Nos means a shorter than lifelong course of anticoagulation – the interval to be recorded in the notes and as text associated with the code..

The doctor should also fully explain anticoagulation to the patient and add warfarin to the repeat medication.

Bloods are taken as requested. Doctor indicates new dose and interval, which receptionist records. Receptionist then rings patient with details.

• DIGOXIN

Toxic side effects a possibility in elderly, hypokalaemia, heart block, high doses. The BNF says that regular level monitoring is NOT needed unless there a problems.

Digoxin level - no dose for at least 6 hours prior to BT.

Follow up – opportunistic or if problems.

• THYROXINE

Doctors, please remember that TFT is only an aide to dose monitoring. Clinical assessment is just as important.

Follow up – opportunistic, scrip right side messages, ?stickers on scrips, annual audit.

Annual TFT. Can be taken at any time.

• ANTIEPILEPTICS, LITHIUM and THEOPHYLLINE

Plasma concentrations of these drugs is notoriously variable due to individuals, compliance, interactions with other antiepileptics and other drugs and growth in children. Maintaining plasma levels in the reference range ensures the greatest effect with a minimum of side effects. Note – Valproate needs no monitoring.

Follow up – opportunistic, scrip right side messages, ?stickers on scrips. Annual audit.

Annual.

Phenytoin - immediately before oral dose.
Carbamazepine - immediately before oral dose.
Phenobarbitone - immediately before oral dose.
Theophylline - immediately before oral dose.
Lithium - 12 hours after last dose. – Annual TFT, UE.
Time taken for drug levels to reach steady state.
Digoxin-5-7 days. Longer if impaired renal function.
Phenytoin - very variable.
Carbamazepine - 2-6 days.
Valproate - 2-3 days.
Theophylline - Adults 2 days.
Lithium - 3-7 days

• HYDROXOCOBALAMIN

If the patient only has pernicious anaemia, up to 3 monthly injections will by definition give more than adequate replacement. It is wise to follow up as these patients often have other pathology. It is not advised to do regular TFT of BS.

Follow up – opportunistic, scrip right side messages, ?stickers on scrips, annual audit.

Annual FBC.

• DIURETICS and/or ACE INHIBITORS

Remember, some of these patients will also be having Ues for diabetic checks.

Follow up – opportunistic, scrip right side messages, ?stickers on scrips, annual audit.

Annual UE.

• AMIODARONE

This has all sorts of side effects and does totally unpredictable things to TSH and T4. Clinical assessment of the patients thyroid status is needed as well as a blood test. TFTs can be abnormal in a clinically euthyroid patient and vice versa.

Eye abnormalities, expect patients to present.

Follow up – opportunistic, scrip right side messages, ?stickers on scrips. Annual audit.

6 mly TFT, LFT, FBC, UE. Appointment to see Dr after.

• MINOCYCLINE

Causes liver damage.

Follow up – opportunistic, scrip right side messages, ?stickers on scrips, annual audit.

Annual – LFT, autoantibodies.

• STATINS

The class of lipid lowering drug known as "statins" (cerivastatin, atorvastatin, fluvastatin, pravastatin, simvastatin) can all cause liver damage. It seems this is mainly a problem in the first year or so of treatment. It is suggested to do LFTs before treatment, 1-3 months after and then 6 monthly for 1 yr. This is roughly the interval for lipid checks so could be done same time.

Follow up – nil.

For LFTs to be done whenever lipids are checked for a patient on this medication.

This is intended to be only a brief guide. The full local guidelines are available separately.

• METHOTREXATE

Given weekly for rheumatoid arthritis and psoriasis. Advice varies – below is based of SDHC Rheumatol Unit.

Follow up – opportunistic, 6 monthly audit, right side message.

Before commencing therapy - FBC, LFT’s and assess renal function

On therapy - Every 2 weeks for 3 months then FBC monthly.

LFT’s, UE, LFT every monthly.

• PENICILLAMINE

Watch for platelets falling and proteinuria.

Follow up – opportunistic, 6 monthly audit, right side message.

FBC+VISC + URINE - weekly for 1 month > 2 weekly for 2 months > Monthly from 3 months.

• SULPHASALAZINE

Blood dyscasias, hepatitis, proteinuria. Look out for fever, sore throat etc.

Follow up – opportunistic, 6 monthly audit, right side message.

FBC - 2 weekly for 3 months > then every 3 months.

LFT – 3 monthly

• HYDROXCHLOROQUINE

Has toxic eye effects but not thought to be a problem in the doses used locally. For ophthalmological referral and follow up if doses 400mg or above/day. Look out for blood dyscrasias.

Follow up – opportunistic, 6 monthly audit, right side message.

FBC, LFT – 2 monthly.

• AZATHIOPRINE

Look out for blood dyscrasias, fever, nausea.

Follow up – opportunistic, 6 monthly audit, right side message.

FBC – weekly for 2 months then monthly.

LFT - 3 monthly.

• GOLD

Blood dyscrasias and proteinuria.

Follow up – opportunistic, 6 monthly audit, right side message.

Urine testing weekly (patients can do themselves).

FBC+VISC – weekly for 20 weeks the > monthly.

• CYCLOSPORIN

Side effects, renal, hypertension, anemia, etc++

For patients with Rheumatoid or Psoriasis - Monthly BP, UE, creatinine, LFT, FBC.

For transplant patients – as above. Generally seems to be done by transplant units.

• METHYLPHENIDATE AND DEXAMPHETAMINE

Given to children for ADHD. Potential side effects; insomnia, headaches, nervousness, fits, hypertension, growth retardation.

Follow up – parents told on starting, 6 monthly audit, right side message.

Height, weight (to be charted on growth chart), BP, FBC – on initiation > after 3 months > every 6 months

• ERYTHROPOIETIN

This is used to stimulate blood production in renal patients. Dose changes to be done by the renal team.

Follow up – opportunistic, 6 monthly audit, right side.

FBC, BP – monthly.

Ferritin – every 2 months.

These are in the shared care folder but do not need input from nurse/phlebotomist.

• SOMATOSTATIN ANALOGUES (OCTREOTIDE AND LANREOTIDE)

These are growth hormone related agents which are used to control acromegaly and carcinoid tumours. They can cause, GI symptoms, gallstones, impaired glucose tolerance.

Follow up – 12 monthly audit.

Gall bladder ultrasound – 6 monthly.

These are zoladex, prostap, de-capeptyl, suprecur, suprefact. They control production of sex hormones via the pituitary. They have numerous side effects but no specific blood monitoring is needed.

This is a new antipsychotic. Side effects, drowsyness, anxiety, extra-pyramidal reactions. No routine monitoring is needed unless there are side effects.

Used in patients with cystic fibrosis. It is an enzyme which breaks up sputum. No GP based monitoring is needed.

• ACAMPROSATE

Used to reduce craving in alcoholics. No specific GP monitoring.

Ask patient to attend optician 6mly for field tests.

• CLOMIPHENE

No specific GP monitoring except checking for adverse effects, precautions and Cis.

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Last modified: September 28, 2005