Steroids and Cholesterol Flashcards
Discuss the actions of oestrogens
Anabolic Increased HDL Water and Sodium Retention Decreased Bone Resorption Increased Blood Coagulability
Discuss the side effects of oestrogen
Breast tenderness Nausea Decreased glucose tolerance Vomiting Water retention Thromboemolism Endometrial hyperplasia -> Cancer
Discuss the actions of progesterone/progestogen
Secretary endometrium Anabolic Increased mineral density Fluid retention Mood change
Discuss the side effects of progesterone/progestogen
Weight gain Fluid retention Acne PMS Depression Irritability
Discuss the actions and side effects of testosterone
Secondary sex characteristics, anabolic, voice changes
Acne
Aggression
Adverse metabolic effects on lipids
Discuss the problem with 21-hydroxylase deficiency.
Converts 17α-OH progesterone to cortisol to provide negative feedback to hypothalamus and pituitary.
Absence causes excessive conversion to testosterone.
Describe the activation of testosterone in the body
5α-Reductase converts to 5α-dihydrotestosterone which is more potent than testosterone.
Discuss the transport of gonadal steroids in the body
Bound to sex hormone binding globulin (SHBG)
Discuss the metabolism, excretion and action of sex steroids
Metabolised in liver (prog metabolised by 1 passage through liver).
Renal excretion as glucuronides and sulphates.
Binding to nuclear receptors to stimulate transcription.
Discuss the different types of COCP
Monophasic, Triphasic or Daily (+placebo)
20->50mg/day oestrogen (ethinylestradiol or mestranol)
Progestogens (drospirenone or norelgestromin)
What is the mechanism of action of the COCP?
Suppression of ovulation by inhibition of FSH and LH.
Adverse effect on cervical mucus to reduce sperm penetration.
Adverse effect on endometrium to prevent implantation.
Discuss the metabolism of COCP
Metabolised in the liver by CYP450 enzyme.
Efficacy is reduced by inducers (carbamazepine and phenytoin)
What are the side effects of taking the COCP?
Venous thromboembolism MI Hypertension Decreased glucose tolerance Increased risk of stroke with focal migraine Headaches Mood swings Cholestatic jaundice Precipitate porphyria
Discuss the use and action of the progestogen only pill
28 day course of levonorgestrel, norethisterone or etynodiol diacetate
Cervical mucus ‘plug’
Adverse effect on myometrium
What is the major disadvantage with pop?
Poor cycle control
What other forms can progestogen be in other than the PoP?
Implanon or vaginal ring
MPA and Etonogestrol
Discuss the types of emergency contraception
Levonorgestrel (1.5mg) in 72 hours or Ullipristal Acetate (30mg) in 120 hours
What is the main aim of post menopausal HRT?
Symptom control
Preventing osteoporosis a bonus
What is the general make up of HRT medication?
Oestradiol 1-2mg daily + Premarin 0.625-1.25mg daily
May be combined with medroxyprogesterone acetate, norethisterone and duphaston
What are the two main routines for HRT? And what are the advantages of each?
Sequential combined = bleed every month (protective)
Continuous combined = no period but less protective
What are the main risks of HRT?
Endometrial and Ovarian Cancer Breast cancer IHD Stroke Thromboembolism Uterine bleeding
A 55 year old patient is post menopausal. What questions should be asked before prescribing hormone replacement therapy?
Has she had a hysterectomy? If so unopposed oestrogen is fine
Still has womb? NO unopposed oestrogen
Discuss use of anti i) oestrogens; ii) progesterone; iii) androgens.
i) weak oestrogens that block receptors (clomiphene and tamoxifen).
ii) mild agonist -> sensitise uterus to prostaglandins for use in termination of pregnancy or inducing of labour.
iii) competes with dihydrotestosterone found in COCP (ciproterone).
Discuss the effects of SERM
Selective oEstrogen Receptor Modulators (Raloxifen)
Prevent osteoporosis
No proliferation in endometrium or breast
Decreased risk of invasive breast cancer in post meno women
Increased hot flushes
