Antidiabetic Drugs, Anti-thyroid Drugs and Oral Contraceptives Flashcards by JJ Doh

Where are the hormones thyroxine/levothyroxine (T4) and tri-iodothyronine (T3) made from?

(Both under the control of TSH)

Thyroid gland

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What hormone is produced by C (parafollicular) cells of thyroid gland?

Calcitonin

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Hypothalamus -> Anterior Pituitary -> Thyroid Gland
State the hormones released at each structure.

TRH -> TSH -> T4 and T3

TRH = thyrotropin releasing hormone; TSH = thyroid stimulating hormone

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What ions are thyroid hormone production dependent upon?

Iodide

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What are thyroid hormones stored as?

Thyroglobulin

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Thyroglobulin undergoes _________ to release hormones

Proteolysis

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Which is more potent - T3 or T4?

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What does T4 become after undergoing transformation in the tissues?

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What do the T3 and T4 hormones influence?

DNA transcription and thus protein synthesis

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What do thyroid hormones do?

Regulate growth: brain development
Calorigenic effects: increase O2 consumption (effect on BMR)
Metabolic effects: transform cholesterol to bile salts; increase lipolysis; increase blood glucose; increase metabolic rate
Cardiovascular effects: direct; indirect (increase sensitivity to catecholamines via beta receptor expression)

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What are the causes of hypothyroidism in children?

Congenital hypothyroidism (causing cretinism)
Hashimoto’s thyroiditis (acquired autoimmune disease; usually affect teens; most common cause of hypothyroidism)

Cretinism: intellectual disability,small stature,thick facial features

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What are the causes of thyroid hypofunction in adults?

Autoimmune destruction
Post surgery

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What are the clinical features of myxoedema which is caused by thyroid hypofunction?

Puffiness of skin
Exopthalmous (deposition of protein and mucopolysaccharides leading to abnormal protrusion of eyeballs)

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What does thyroid hypofunction cause?

Impaired immune response

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What is the second most common endocrine disorder after diabetes mellitus?

Thyroid disease

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What is the treatment of thyroid hypofunction?

Levothyroxine sodium (orally) for maintenance

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What autoimmune disease can be acquired and cause hyperthyroidism?

Graves’ disease (diffuse goitre)

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What clinical features will be present in patients with thyroid hyperfunction?

Anxiety
Tremor
Increase heart rate
Muscle weakness
Insomnia

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What are the 3 methods of treating hyperthyroidism?

Antithyroid drugs eg carbimazole and propylthiouracil
Potassium iodide
Radioactive iodine

Control the production of T3 and T4

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What are the 2 antithyroid drugs?

Carbimazole
Propylthiouracil

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How do carbimazole and propylthiouracil work?

The ‘thionamides’ or ‘thiourylenes’ prevent incorporation of iodine into T3 and T4.
Propylthiouracil also stops conversion of T4 to T3.

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What is the most commonly used drug to treat hyperthyroidism in the UK?

Carbimazole

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When is propylthiouracil used instead of carbimazole?

If intolerant or sensitive to carbimazole
In 1st trimester of pregnancy

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When is iodine given as treatment for thyroid hyperfunction?

Short term only prior to partial thyroidectomy

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What are some unwanted side effects of antithyroid medications?

Thionamides: agranulocytosis, urticarial rash, hepatitis, arthralgia Iodine-containing preps: hypersensitivity reactions (angioedema) Radioactive iodine: hypothyroidism

What influences calcium and phosphate metabolism?

Calcitonin

What hormone does calcitonin oppose?

Parathyroid hormone (PTH)

What does calcitonin produce?

Hypocalcaemia Hypophosphataemia

How does calcitonin work?

Inhibition of osteoclasts | Osteoclasts break down bone and release calcium into bloodstream

What is calcitonin used to treat?

Hypercalcaemia Paget's

What are the different types of calcitonin and how to administer calcitonin?

Salmon, eel, pig or synthetic human calcitonin SC or IM injection

What needs to be avoided in uncontrolled hyperthyroidism?

Adrenaline

What could Candidiasis be a possible indication of?

Reduced immune response in hypothyroidism

What medications may taste disturbance be caused by?

Calcitonin Carbimazole Propylthiouracil

What can cause damage to salivary glands?

Radioactive iodine

What is type 1 diabetes mellitus due to?

Deficiency of insulin

What is type 2 diabetes mellitus due to?

Decreased insulin secretion or resistance to insulin action

How to treat diabetes?

Supply insulin Increase insulin intake Decrease glucose intake Decrease glucose uptake

What can inactivate insulin?

Gut enzymes | therefore cannot be taken intraorally

Insulin can be administered parenterally. For maintenance, __________ injection. For emergency, ___________ injection.

Subcutaneous, intravenous

What is the insulin adminestered through inhalation called?

Afrezza | Not currently available on NHS

What type of insulins are there?

Animal insulin Human insulin eg Humulin Human analogue insulin (subgroup of human insulin) eg rapid acting, long acting, intermediate acting

What are some examples of insulin regimens?

Once-daily insulin regimen Twice daily insulin regimen or Biphasic Basal-bolus regimen / multiple daily injection therapy Continuous subcutaneous insulin infusion (CSII) / insulin pump therapy

Once-daily insulin regimen: Type _ diabetes supplemental to ______ __________

2, oral hypoglycaemics

Twice daily insulin regimen or Biphasic: Mix of short and _______ acting insulin

Intermediate

Basal-bolus regimen / multiple daily injection therapy: Type _ commonly More flexible and tailorable to meal Use of basal intermediate or long acting and separate short or rapid acting insulin

CSII / insulin pump therapy: Type _ Rapid insulin continuously Adjustable

Soluble insulin may cause ____ and _____ of the salivary glands

Pain, swelling

What may inhaled insulin cause?

Dry mouth

If GA involved dental procedure, usually involves checking __________.

HbA1c

Which drug class can produce hypoglycaemia? | And should be used with caution?

NSAIDs

What drug class can antagonise the hypoglycaemic effect of insulin?

Systemic steroids

When should oral hypoglycaemics be used?

Only after >3 months of diet and exercise to try and control T2 diabetes and afterwards as a supplement to lifestyle factors

What are some classes of oral hypoglycaemics?

Sulphonylureas Biguanides Thiazolidinediones (glitazones) Alpha-glucosidase inhibitors

Sulphonylureas are used to _________ insulin secretion, but must have functional beta cells. They are for those who are not _________ or those who cannot take ________. Examples of sulphonylureas include _______, _______ and tolbutamide. Sulphonylureas can be used in combination with other oral hypoglycaemic drugs.

Augment, overweight, metformin, gliclazide, glipizide

Sulphonylureas are used to _________ insulin secretion, but patients must have functional beta cells. They are for those who are not _________ or those who cannot take ________. Examples of sulphonylureas include _______, _______ and tolbutamide. Sulphonylureas can be used in combination with other oral hypoglycaemic drugs.

Augment, overweight, metformin, gliclazide, glipizide

Biguanides can only act in the presence of ______ so it will only work in patients with functional beta cells. Biguanides decrease ____________ and increase peripheral utilisation of __________. They are first choice of drug for _______ patients. An example of biguanide is metformin.

Insulin, gluconeogenesis, glucose, overweight

Other oral hypoglycaemic drugs: _________ inhibits intestinal α-glucosidases delays the digestion and absorption of starch and sucrose ‘________’ (pioglitazone) reduce peripheral insulin resistance, leading to a reduction of blood-glucose concentration ‘Gliptins’ (Alogliptin, linagliptin, saxagliptin) inhibit dipeptidylpeptidase-4 to increase insulin secretion and lower glucagon secretion ‘______’ (Exenatide, albiglutide, dulaglutide) bind to, and activate, the GLP-1 (glucagon-like peptide-1) receptor to increase insulin secretion, suppress glucagon secretion, and slow gastric emptying ‘______’ (Canagliflozin, dapagliflozin, empagliflozin) reversibly inhibit sodium-glucose co-transporter 2 (SGLT2) in the renal proximal convoluted tubule to reduce glucose reabsorption and increase urinary glucose excretion

Acarbose Glitazones Gliptins Tides Gliflozin

What oral hypoglycaemic drug may cause lichenoid eruptions, erythema multiforme and oral neuropathy?

Sulphonylureas

What oral hypoglycaemic drug can produce taste disorders?

Metformin

How to treat patients who are having hypoglycaemic episodes?

Oral glucose 10-20g (3 sugar lumps/2 teaspoon of sugar/100ml sugary drink/Glucogel) If unconscious: 1mg IM or SC glucagon; less commonly available IV glucose 20-50ml of a 50% dextrose solution

Combined oral contraceptive: ________ and ________. __ days active, __ days inactive.

Oestrogen and progesterone. 21, 7.

____________-only oral contraceptive: continuous use. 'mini pill'. Used when oestrogens contra-indicated eg predisposition to venous thrombosis.

Progesterone

For patients who do not want to take progesterone-only oral contraceptive tablet everyday, what can they opt for?

Progesterone-only depot injection or implant

What is in 'morning after' pill?

Oestrogen only

How does oestrogen work?

Inhibits ovulation by inhibition of FSH

How does progesterone work?

Inhibits release of LH, changes the endometrium to discourage implantation and thickens cervical mucus (prevents sperm from entering uterus)

What effects do oral contraceptives cause that are related to dentistry?

Increase plaque-induced inflammation Increase gingival crevicular fluid Gingival pigmentation Appear to increase the incidence of dry socket Improves severity of oral aphthous ulceration related to menstruation May increase post-operative pain

Anticonvulsants eg __________ (enzyme-inducing) can stop oral contraceptives from working.

Carbamazepine

What type of antibiotics will cause a problem when taking together with oral contraceptives? Give an example.

Enzyme-inducer eg rifampicin

Are routine dental antibiotics enzyme-inducers?

What should be recommended to patients who are taking enzyme-inducing antibiotics while using hormonal contraception?

Additional contraceptive methods such as condoms or IUD

If antibiotics other than rifampicin and rifabutin are taken, additional contraception is not usually needed. However, concerns arise when symptoms such as _________ or _________ come up. The effect of the antibiotics on gut flora and enterohepatic cycling can affect the absorption of the oestrogen pills.

Diarrhoea, vomiting.

What are the two drugs we need to be concerned about interacting with oral contraceptives?

Enzyme-inducing anticonvulsants eg carbamazepine Antibiotics (enzyme-inducing eg rifampicin; non-enzyme-inducing but cause diarrhoea or vomiting)

Antidiabetic Drugs, Anti-thyroid Drugs and Oral Contraceptives Flashcards

(74 cards)