Little TV Addict

Pain relief

NSAIDS

1. Diclofenac (Voltarol pain-eze) – 14 yrs
2. Ibuprofen tabs                                – 12 yrs
3. Aspirin                                                – 16 yrs
4. Naproxen (Feminex ultra)         - 15 yrs

Migraine Tx

1. Sumatriptan (Imigran)   - 18 – 65 yrs

GI Tract

1. H2-antagonist i.e. Ranitidine   - 16 yrs
2. Omeprazole 10mg                         - 18 yrs

Cough & Cold & Hay fever

1. Decongestant (depends on the license holder)      - 6 or 12 yrs
2. Fluticasone or Beclometasone                                      – 18 yrs

Eye Care

1. Chloramphenicol        – 2 yrs

Skin Care / Antifungals

1. Hydrocortisone cream   – 10 yrs
2. Canestan for thrush         - 16 – 60 yrs
3. Terbinafine (Lamisil )      – 16 yrs , Lamisil Once – 18 yrs

Sleeping

1. Diphenhydramine (Nytol)       – 16 yrs

Sulphonylureas (SU)

• Augment insulin secretion
• Not for overweight patient
• Su-induced hypo persist for very long & must be treated in hospital
• LA – glibenclamide, chlorproramide    SA – Gliclazide, tolbutamide
• Omitted in the morning of surgery
• SA SU can be used in renal impairment

Cautions

• Contra-indicated in pregnancy and breast feeding
• severe hepatic impairment
• ketoacidosis

* Chlorpropamide – many side effects, no longer recommended , facial flushing with alcohol

Biguanides (metformin)

• Decrease gluconeogenesis, increase peripheral utilisation of glucose
• For overweights
• omit on morning of surgery, give insulin
• Side effects – GI, anorexia, taste disturbance,

Caution

• lactic acidosis with renal impairment
• can be given during pregnancy & breast feeding

Thiazolidinedione (pioglitazone)

• reduce peripheral insulin resistance
• can be used with SU if Metformin unsuitable
• Side effects – oedema, visual disturbance, weight gain

Caution

• heart failure
• ACS
• IHD
•  Liver toxicity
• risk of bone fractures

Acarbose

• delays digestion and absorption of starch and sucrose
• flatulence and GI problem (antacid not useful)
• For hypo, use glucose NOT sucrose (acarbose interferes with sucrose absorption)

 Nateglinide & repaglinide

• stimulate insulin release
• nateglinide only licensed to be used with metformin
• rapid onset and short duration of action

Sitagliptin & vildagliptin

• increase insulin secretion and lower glucagon secretion
• Liver toxicity

Tx – Diabetic Ketoacidosis

• fluid and electrolytes (NaCl, KCl- prevent hypoK by insulin)
• IV soluble insulin (not stopped before SC insulin started)
• Sodium Bicarbonate infusion (Extreme cases)

Tx – Hypoglycaemia

• oral glucose 10-20g ie lucozade, dextrogel, repeated in 10-15mins
• glucagon inj (unconscious)
• Iv glucose (hypo emergency)
• carbohydrate asap

Methotrexate 

 CSM

1. Blood count – bone marrow suppresion, risk of toxicity increased by concomittent use of anti-folate agent
2. Liver Toxicity – liver cirrhosis, discontinue if any abnormalities
3. Pulmonary Toxicity – seek medical attention if dyspnoea, cough or fever, discontinue if pneumonitis suspected
4. Aspirin and NSAIDs – Avoid OTC sales, if they are used, require monitoring
5. Avoid conception for at least 3 months after stopping

Megaloblastic anaemia is caused by the impaired of DNA synthesis, which is usually due to Vitamin B12 and Folate deficiency. It can happen through 2 ways :

i. The inhibition of DNA synthesis by cytotoxic drugs

ii. The reduction of vitamin B12 or folate levels i.e. trimethoprim, antiepileptics

When given at therapeutic dose, trimethoprim, a folate reductase inhibitor, do not normally induce megaloblastic anaemia, but may worsen the folate deficiency.

If megaloblastic anaemia develops in someone who is on epileptic drugs, folic acid is recommended.

List of drugs associated with megaloblastic anaemia :

• Antiepileptics
• Trimethoprim
• Alcohol
• Methotrexate
• Nitrofurantoin
• Sulfasalazine
• Oral contraceptive
• Pyrimethamine
• Triamterene

Before I head to bed, I’d like to just jot down all the important points I have picked up today from my revision. I’v always done this at uni, summarizing a topic before I continue with the next, for me, by doing this, I can remember better. How about you?

Hypertension  

Normal                                     : <130 / <85 mmHg
Grade I Hypertension        : >140 / >90 mmHg

BHS guidelines recommend treatment to be considered if grade I or above.

People entitled to exemption (part XVI DT)

Cancer patients (recently added) - exemption certificate last for 5 years, all prescription items allowed, not just anti-cancer drugs. Can be used till their end date even if patient’s cancer treatment finishes.

Hyperthyroidsm is not exempted

Misoprostol

Prostaglandin analogue, can increase uterine tone, also been used to induce abortion,  may be teratogenic, avoid use during pregnancy, unless effective contraceptive measures taken.

Amiodarone

• long half-life, up to several weeks
• can develop corneal microdeposits, drivers may be dazzled by headlights at night
• possible phototoxic reactions
• contains Iodine, can cause hypo or hyperthyroidsm
• pneumonitis  if SOB or cough develops
• hepatotoxicity
• taste disturbances
• slate-grey skin discoloration

Theophylline

• can cause hypokalaemia when used with beta2 agonist
• heart failure, cirrhosis, viral infections increases the plasma-theoph level
• smokers, chronic alcoholism, decreases the plasma-theoph level
• increases risk of convulsions when used with quinolones

CSM warning – quinolones may induce convulsions, taking with theophylline can increase the risk (side effect of theophylline includes convulsions), quinolones taken with NSAIDS could also cause convulsions.

Quinolones – causes tendon damage too

GOUT

Acute and chronic gout treated differently. 1st line Tx for acute gout involves NSAIDS, but not aspirin.2nd line is Colchicine when NSAIDS is contra-indicated, particularly useful for heart failure, as colchicine does not cause fluid retention. 3rd line is oral or parenteral corticosteroids.

Chronic gout is treated with Allopurinol (reduces uric acid), which should never be started during an acute attack, as it is not effective. Allopurinol is started 1-2 weeks after the attack has settled, NSAIDS/colchicine continued for at least 1 month.

NSF/clinical standards

• sets national standards and define service models for a defined service or care group
• the role of clinical standards is to promote public confidence that the services provided by the NHS are safe and that they meet nationally agreed standards, and delivering the highest possible standards of care

One unit of alcohol is 10ml (1cl) by volume, or 8g by weight, of pure alcohol (patient.co.uk)

One hour is required to clear one unit of alcohol

Picture credit – bbc.co.uk

A friend asked me this today, try it.

Does alcohol affect any of these drugs?

Allopurinol, Amiodarone, Logynon, Warfarin, Methotrexate

Alcohol interactions

Eventhough alcohol interacts with a lot of drugs, but only several will have significant effect.

• Antibacterial i.e. Metronidazole – disulfiram-like reaction
• Anticoagulant i.e Coumarins, Phenindione
• Antidepressants i.e. MAOi, TCA, Mirtazapine

I guess you know the answer now!

I was looking through the new protocol for EHC(Emergency hormonal contraception) from the Torbay NHS Care Trust. I found something useful and worth sharing. It’s the list of  Hepatic Enzyme Inducing Drugs, I’v always wanted to come up with a list myself, but I just havn’t got to it. This group of drugs accelerates metabolism and reduces the efficacy of many drugs especially drugs with a narrow therapeutic window i.e theophylline, it is also important to know that they do the same for contraceptive steroids. I think the 1st few on the list are the more common List of hepatic enzyme inducing drugs .

• Carbamazepine
• Griseofulvin
• Phenytoin
• Rifampicin
• St John’s Wort
• Barbiturates
• Modafinil
• Topiramate
• Primidone
• Tacrolimus
• Oxcarbazepine
• Ritonavir
• Rifabutin
• Bosentan
• Certain PPI
• Certain HIV drugs

For me, I try to remember the 5 that are highlighted in red, to make it easier, I came up with an acronym – C-GPRS, hope that was helpful!! Leave a comment to add any others to the list!

A friend of mine asked me a few question during our little discussion today.  I noticed something that is important, worth mentioning.  The questions mainly involved digoxin, but it can be very confusing if you dont know your facts well.

Which drugs interacts with cimetidine?

Digoxin, Warfarin, or Phenytoin

Which drug has to be dispensed by Brand?

Lithium, Theophylline, or Digoxin

Which drugs has a narrow therapeutic index?

Theophylline, Lithium, or Digoxin

Which drugs require monitoring of their serum-drug levels?

Lithium, Phenytoin, or Warfarin (let’s replace this with Digoxin)

Which drug(s) interact with St John’s Wort?

Digoxin, Phenytoin, or Warfarin

 

Explanation

1. Cimetidine – p450 enzyme inhibitor, increases the plasma level of many narrow therapeutic index drugs i.e phenytoin, carbamazepine, s.valproate, warfarin, theophylline, BUT not DIGOXIN!!

2. Brand specific prescribing is vital for most narrow therapeutic index drugs i.e. Lithium and Theophylline, BUT not DIGOXIN!!

3. It is important to remember besides Lithium and Theophylline, DIGOXIN also has a Narrow Therapeutic Index

4. Most Narrow therapeutic Index drugs require serum-drug level monitoring including Lithium and Phenytoin, BUT not WARFARIN (INR monitoring) or DIGOXIN (refer to BNF page 73- regular monitoring during maintenance treatment is not necessary unless problems are suspected)

5. St John’s Wort – enzyme inducer, which reduces the efficacy of drugs affected i.e. Digoxin, Warfarin, Phenytoin (and some other antiepileptics)

Key things to remember about DIGOXIN

• Long Half-Life
• Hypokalaemia increases risk of digitalis toxicity
• Indicated in heart failure, arrythmias
• Side effects are N+V, arrythmias, diarrhoa, Blurred vision

Important interactions

Digoxin + Diuretics

- Thiazides and Loop – can cause hypokalaemia which increases risk of Digoxin toxicity

- Spironolactone – can increase plasma concentration of Digoxin

Other interactions that could lead to an increase in Digoxin plasma concentration include :

- Amiodarone

- Chloroquine

- Itraconazole

St John’s Wort causes a reduction in the plasma concentration of Digoxin

High strength pancreatin (Pg 70,71) 

• Can cause colonopathy in children with cystic fibrosis – age 2 and 13 yrs
• Pancrease HL, Nitrizym 22, Panzytrat 25000 should not be used for < 15 yrs with cystic fibrosis
• Increases risk with the use of laxatives
• Councelling – adequate hydration
• Taken with meals, as pancreatin is inactivated by stomach acid, can take H2 antagonist an hour before hand

High Strength Prep : Creon 40000, Nutrizym 22, Pancrease HL

Background knowledge about Pancreatin

• aids digestion of starch, protein, fat
• secreted by pancrease
• reduction or loss of secretion in cystic fibrosis, pancreatectomy, gastrectomy