Download Ex: OrthoEvra

The Family Practice Newsletter
The Ohio University College of Osteopathic Medicine
The Ohio Northern University Raabe College of Pharmacy
Doctors Hospital Family Practice
Volume 5, Issue 5
January, 2006
Guidelines for the Selection of Hormonal Contraceptives
Laura Oinonen, Ohio State University Doctor of Pharmacy Candidate
With such a large selection of hormonal contraceptive (HC) options available for women today, it is important to
have some guidelines when selecting one for a given patient. Unless otherwise contraindicated or intolerable, most women
find success using a combined contraceptive product, which contains ethinyl estradiol(EE) and a progestin. Depending on
tolerance, many women can safely and effectively be started on 35 micrograms or less of EE6. If an ample trial period has
been given and the patient is experiencing early or mid-cycle breakthrough bleeding (BTB), spotting, or hypomenorrhea, the
estrogen component strength selected may be too low 6. If nausea, bloating, breast tenderness, increased BP or headache is
experienced, the estrogen component strength may be too high6.
Choosing the progestin portion of the formulation, however, can prove to be a bit more challenging. The available
progestins used in HCs vary according to potency, as well as estrogenic, anti-estrogenic, and androgenic activity. Select one
based on the patient’s characteristics and adjust, if needed. Too much progestin may lead to breast tenderness, headache,
fatigue, or changes in mood, while too little may lead to late BTB6. If the progestin component selected has too much
androgenic activity, some side effects observed may be characteristic of those seen in an androgenic excess patient, including
acne, oily skin, increased appetite, weight gain, hirsuitism, decreased libido, increased breast size and/or tenderness, and
changes in lipid profiles6.
Hormonal Contraceptive
Progestin-Only Pills (POPs)
Ex: Camila, Micronor, NorQD
Combined Oral Contraceptives -progestin and an estrogen in
various strengths in mono, bi or
tri-phasic formulations
Extended
cycle
pills:
Seasonale
(3 cycles taken continuously
without sugar pill may lead to
sometimes desirable 4 periods
per year 6)
Other combined contraceptives:
Vaginal ring
Ex: NuvaRing
Transdermal patch
Ex: OrthoEvra
IUDs implanted with hormones
Ex: Mirena (progestin only)
The patient it IS GOOD for
-Women who desire HC while breastfeeding
-Those who cannot take COCs due to
estrogen component
-Majority of women since they are available
in various strength formulations
-Good form if woman desires HC for cycle
regulation or contraception
-Pregnancy can be achieved normally after
discontinuation of product if desired.
The patient it is NOT GOOD for
-Those who cannot take the pill consistently
on time each day (6)
-Women who desire a non-oral option dosed
once a month (those who may not adhere to
once daily dosing of oral method)
-Releases a steady stream of hormones over
a 3 week period, reducing fluctuations and
possibly AEs
-Women who desire a non-oral method of
HC applied weekly for 3 weeks, then off, to
the skin
-Women who have had at least one child,
who are in a monogamous relationship,
breast-feeding mothers, those who desire
effective contraception for up to five years
-Those with very low adherence potential
who do not desire sterilization and do not
desire injection therapy (below)
-Woman must be comfortable keeping ring
inside vagina for 3 weeks
-Some women feel the ring in place during
intercourse or have trouble with expulsion due
to body shape
-Any women who has contraindications to use
of COCs
-Those who are breastfeeding
-Women who are over 90kg (less effective)4
-Women who may not want a visible/irritating
patch on skin
-Device is placed in the uterus for up to five
years, have to go to physician for implantation
and removal, may cause cramping initially
-Those who desire an estrogen component to
their HC
IM, SQ medroxyprogesterone
injection, implants
Ex: DepoProvera IM, SQ,
Norplant
-Women who are breastfeeding
-Women who want an option that lasts 3
months with no estrogen and no internal
device
-Women who are concerned about weight gain
should be warned of this possible AE
-Those who desire an estrogen component to
their HC
Above table adapted from reference 6
One of the newer COCs available is Yasmin (EE 0.03mg/ drospirenone 3mg). Drospirenone is a spironolactone-like
moiety which may add a mild diuretic-like effect during its use. This ingredient, unlike other progestins, has anti-androgenic
and anti-mineralocorticoid activity5. This may be especially useful in women with androgen-excess induced acne or
hirsuitism (such as women with PCOS).3,7
Other Issuses with hormonal contraception
Two COCs have been FDA approved for the treatment of acne, Ortho Tri-Cyclen and Estrostep5. Trials have shown
that improvements in acne or hirsuitism requires several months of use of the product. Due to its unique structure, Yasmin
can exhibit some potassium-sparing properties6. Serum potassium levels should be checked after the 1 st cycle, especially in
high risk patients. Concomitant use of Yasmin with ACEi, ARBs, and spironolactone may also potentiate hyperkalemia,
which should be closely monitored over time if these medications are used together. Due to its lack of androgenic activity,
its progestin component may also minimize any progestin-induced weight gain.
HCs are metabolized via many similar CYP450 enzymes as other medications and may compete for or depleate
there activity (ie, cause a drug-drug interaction). The following table lists some drugs that increase enzyme activity and
therefore may decrease COC levels in the body, thereby making them less effective. If these medications are selected to be
used with COCs, the patient should be advised of the increased risk of failure 8.
Drug Class
Anticonvulsants
Generic (Trade)
Barbiturates (phenobarbitol)
Carbamazepine (Tegretol)
Phenytoin (Dilantin)
Topiramate (Topamax)
Recommendation
Use alternative contraception, use higher dose OC if appropriate
-Could use Valproate (Depakene), levetriacetam (Keppra), and gabapentin
(Neurontin) (These do not decrease effectiveness of OCs)
Anti-Infectives
Rifampin (Rifabutin)
Griseofulvin (Grisactin)
Erythromycin (E-Mycin)
Penicillins, Tetracyclines
Use back up method during treatment
-Rifampin use requires back-up method one month after d/c of drug
-Advise patient it may be wise to use back-up method during and for a
week after treatment
-Conflicting information exists regarding this interaction. GI bacteria are
decreased with antibiotic use, which may interfere with enterohepatic
circulation, thereby reducing effectiveness of OC. D/V caused by some
antibiotic use may also be responsible for decreased gut absorption of OCs
-Advise patient to disclose all herbal, supplement, OTC use to physician
and pharmacist
-Reports of unintended pregnancy or break-through bleeding with use5
-Advised back-up birth control use if desire to take these products
Broad Spectrum Antibiotics
OTC Herbals, Supplements
St. John’s Wort
Garlic preps that contain
allicin
Above table adapted from table found in reference 8.
The following medications may increase hormone levels of HC’s, causing side effects, such as: Fluconazole (Diflucan),
ketoconazole (Nizoral), Itraconazole (Sporonox), and atorvastatin (Lipitor-moderate increase reported)8.
Some common interactions where HCs may increase effectiveness of other medication levels include: Chlorpromazine
(Thorazine), clozapine (Clozaril), various benzodiazepines metabolized by oxidation, such as diazepam (Valium), alprazolam (Xanax), and
caffeine8.
Other medications may have reduced effectiveness when taken with COCs including: Lamotrigine (Lamictal) and various
benzodiazepines metabolized by glucuronidation such as lorazepam (Ativan) and temazepam (Restoril) 8. When any of the above listed
medications are used simultaneously with HC therapy, close monitoring of drug effects should be implemented.
In conclusion, selecting an appropriate HC in women can be challenging. But by asking the correct questions related to
adherence, lifestyle, and other health conditions, the selection process is much easier and can assist in treatment success.
References
1. Body Mass Index, Weight, and Oral Contraceptive Failure Risk. Holt; VL, Scholes, D; Wicklund, KG et al. Obstetrics and Gynecology. 2005; 105: 4652.
2. Contraceptive Use by Diabetic and Obese Women. Chuang, CH et al. Women’s Health Issues 15(2005); 167-173.
3. Drospirenone for the Treatment of Hirsute Women with Polycystic Ovary Syndrome: A Clinical, Endocrinological, Metabolic Pilot Study. Guido, M et
al. Journal of Clinical Endocrinology & Metabolism. 2004 89(6): 2817-2823.
4. Efficacy of Oral Contraceptives in Overweight Women. Pharmacist’s Letter/Prescriber’s Letter 2005;21(2): 210212.
5. Herb-Drug Interactions: An Overview of the Clinical Evidence. Izzo, AA. Fundamental & Clinical Pharmacology. 2004(19): 1-16.
6. Hormonal Contraception. Pharmacist’s Letter/Prescriber’s Letter 2003; 19(10): 191010.
7. Pharmacologic Treatment of Polycystic Ovary Syndrome. Pharmacist’s Letter/Prescriber’s Letterr 2004; 20(10): 201006.
8. Oral contraceptive (OC) drug interactions. Pharmacist’s Letter/Prescriber’s Letter 2005; 21(9): 210903.