Oral contraceptives listing

Ethinyl estradiol is metabolized in the liver via the cytochrome P-450 system. It is metabolized primarily via CYP450 3A4. When reviewing drug interactions of oral contraceptives, it is important to keep in mind that antibiotic administration during contraceptive use may decrease the efficacy of many combined contraceptives. Refer to Table 45-4 for a list of common drug interactions seen with oral contraceptives.1,31... 

The Advisory Committee on NHS Drugs, when examining oral contraceptives as one of the classes involved in the second phase of the limited list exercise, formed a preliminary position that the more expensive third-generation oral contraceptives should be precluded from availability on NHS prescription on grounds of cost. The outcry from women s groups, family planning practitioners and the medical profession was such that these proposals were never implemented. 

Oral contraceptives, 162 listing, 186, 187 Ordeal bean, as source of physostigmine, 111 Orphenadrine, 42 Ortho-NovuiriSi, 187 Ovral , 186 Ovulation, 105... 

Only one implantable contraceptive preparation is available at present in the USA. Etonogestrel, also used in some oral contraceptives, is available in the subcutaneous implant form listed in Table 40-3. Several hormonal contraceptives are available as vaginal rings or intrauterine devices. Intramuscular injection of large doses of medroxyprogesterone also provides contraception of long duration. 

Although sickle cell disease is sometimes listed as a contraindication to oral contraceptive use, it has been suggested that this may not be justified (309). Women with sickle cell disease need highly effective contraception, because pregnancy is associated with increased morbidity... 

In standard reference works, oral contraceptives are commonly listed as increasing the circulating concentrations of glucocorticoids (82), but variable effects have been reported with different glucocorticoids. 

The most common type of oral contraceptive is the combination preparation and these are listed in Table 61.5. 

Dr. Bill Coleman, for several chemical steps in Syntex s synthesis of the oral contraceptive chlormadinone. With Haldor Christensen, sodium dispersion chemistry led to a superior process for the manufacture of the Eh Lilly herbicide, diphenamid. We devised novel patented chemistry, with the inspiration of Dr. Martin Hultquist, for the manufacture of DDQ. The list could go on and on, but the essence is that in Arapahoe we became chemical process development chemists. We learned that there were no such chemists as steroid chemists, organometallic chemists, heterocyclic chemists, and so on. There are only process development chemists, capable of synthesizing anything. Being scientists in a small company we also learned to accommodate other disciplines and business requirements in creating our chemical processes. 

Today, the major oral contraceptives on the market in the United States are mixtures of the estrogen, 17[Pg.236]

While numerous studies have evaluated the effect of oral contraceptives and postmenopausal hormone replacement on drug clearance, many were flawed by poor study design. Table 21.1 lists studies that were of crossover or sequential design such that each subject was evaluated in the contraceptive phase and placebo phase. These study designs minimize the effect of interindividual variability. In most studies there was no effect of hormonal therapy on drug metabolism, but in some there were interactions that inhibited or increased the metabolism of concurrently administered drugs. 

Innumerable drugs have come under suspicion. Those for which evidence of safety was subsequently found include diazepam, oral contraceptives, spermicides, and salicylates. Naturally the subject is a highly emotional one for prospective parents. A definitive list of unsafe drugs is not practicable. Much depends on the dose taken and at what stage... 

Anticoagulants Antipsychotics Theophylline Oral contraceptives DoxycycUne diminished effect of listed drugs... 

PBS listing on medical grounds, economic factors including cost-effectiveness are taken into account, as required by the National Health Act, 1953. Fixed combination products are seldom considered suitable for inclusion in the PBS. Notable exceptions to this norm are oral contraceptives and combination hormone replacement therapies. Any new listing which has the potential to cost the PBS more than 10 million in the first full year of reimbursement must be approved by the Federal Cabinet. Otherwise, applications are approved by the Health Minister. 

Category Cx a kind of new limited reimbursement list before categorization (oral contraceptives). Co-payment is 80 percent. 

While only steroids against asthma come high on the above lists, the chemical class as a whole plays an unusual role, being the active component of oral contraceptives some anti-asthma drugs some anti-inflammatories and conjugated estrogenic hormone, taken as hormone replacement therapy by meno-pansal women. Some other chemical classes resemble steroids in being therapentically active in a nnmber of areas, and the most important of these are shown in Table 45.3. 

Before discussing the clinical application of these steroidal agents it is well to keep in mind the extraordinary efficacy of this mode of contraception. In Table I we present the data assembled by Venning (31) on the relative efficacy of various contraceptive methods. All of those studied in various experimental trials effectively reduced fertility, but the oral contraceptive most extensively studied (the norethynodrel-estrogen combination) is much the most effective. Indeed, the pregnancy rate listed appears to be attributable to failure to use the method properly rather than to a rare physiological exception to the action of the drug. 

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