Class B drugs

All amphetamines are prescription only drugs under the Medicines Act. Most are also controlled under the Misuse of Drugs Act. Doctors can prescribe them for patients but it is an offence to be in possession of amphetamines without a prescription. Most amphetamines are controlled as class B drugs under the Misuse of Drugs Act. Maximum penalties for possession are 5 years imprisonment plus a fine and for supply are 14 years imprisonment and a fine. If amphetamines are prepared for injection they become class A drugs and increased penalties apply. 

Barbiturates are a Class B drug unless the barbiturate is used in an injectable form It then becomes a Class A drug. 

The maximum penalty for possession of a Class B drug is five years of prison, an unlimited fine (of any amount), or prison and a fine. The maximum fine for supply (trafficking) is a 14-year prison term, an unlimited fine, or both penalties. 

Amphetamines are designated a class B drug in the United Kingdom under the Misuse of Drugs Act 1971. Possession carries a penalty of imprisonment for three months to five years, and trafficking carries a sentence of six months to 14 years. A fine may also be imposed. 

The final type of cannabis product that is likely to be encountered is cannabis oil, more commonly known as hash oil which is obtained by solvent extraction of the herbal or resinous material. There is debate in the legal literature as to whether this constitutes a Class A or Class B drug, the key to which appears to be the presence of cannabidiol. If the latter is present, then the material is treated as a purified form of resin (Class B), while if it is absent, the material is considered to have been prepared, and therefore falls under Class A. 

In the United Kingdom, diamorphine is controlled as a Class A drng, nnder Part 1 of Schednle 2 of the Misnse of Drugs Act, 1971, as is its precursor, morphine. Codeine is controlled as a Class B drug. In addition, the prodncts fonnd as imparities from diamorphine prodnction, namely 3-monoacetyhnorphine and 6-monoacetylmorphine, are controlled as esters of morphine, while acetylcodeine is controlled as an ester of codeine. In the United States, heroin (diamorphine) is controlled as a Schednle I narcotic. 

Richardson, B. P., Engel, G., Donatsch, P., and Stadler, P. A. (1985). Identification of serotonin M-receptor subtypes and their specific blockade by a new class of drugs. Nature 316 126-131. 

Lidocaine (Xylocaine), die representative class I-B drug, raises the threshold of the ventricular myocardium. Threshold is a term applied to any stimulus of the lowest intensity that will give rise to a response in a nerve fiber. A stimulus must be of a specific intensity (strength, amplitude) to pass along a given nerve fiber (Fig. 40-2). 

Snell, L.D. Mueller, Z.M. Gannon, R.L. Silverman, P.B. and Johnson, K.M. A comparison between classes of drugs having phencyclidine-like behavioral properties on dopamine effect i n vitro and dopamine metabolism j n vivo. J. Pharmacol Fxp Ther 231 261-269, 1984. 

B) Angiotensin 11 can act at the AT2 receptor with both classes of drugs. 

Drug B is slightly soluble in water, and its water solubility is pH dependant with higher solubility at higher pH. Drug B has moderate permeability and is a BCS Class IV drug. The initial proposed... 

An example of a class of drugs that interrupt neurotransmitter degradation is the monoamine oxidase (MAO) inhibitors. MAO is a mitochondrial enzyme that exists in two forms (A and B). Its major role is to oxidize monoamines such as norepinephrine, serotonin, and dopamine by removing the amine grouping from the neurotransmitters. Under normal circumstances, MAO acts as a safety valve to degrade any excess transmitter molecules that may spill out of synaptic vesicles when the neuron is in a resting state. MAO inhibitors prevent this inactivation. In their presence, any neurotransmitter molecules that leak out of the synaptic vesicles survive to enter the synapse intact. Receptors are thus exposed to a greater amount of the neurotransmitter. 

After administration, the drug circulates in the blood, primarily as the chloride (for cisplatin), or as another rather inert form (such as the biscar-boxylate in carboplatin). In the blood, also reactions with proteins and rescue agents can take place. Upon passing through cell walls (either actively or passively), intracellular reactions with peptides and proteins may take place, presumably followed by transfer to nucleic acids. Given the strong (kinetic) preference of Pt compounds to react with class-B donor atoms (such as those from thiolates and thioethers), binding to nucleic-acid bases (a thermodynamic end product) must at least occur partially via labile intermediates. 

Figure 6.20 Plot of qo vs. 1/0, for the experimental data of Table 6.1 classified in Class II. The curves denote 90% absorption for two particle sizes (from left to right 10 and 25 pm) assigning Pe// = 2 x lCP2cmmin 1, which corresponds [170] to the mean, Papp = 1.68 x 10 5cms 1 of the Caco-2 permeability values of the data [90]. Drugs located above the curves are fully absorbed (Fa > 0.90) Class II drugs. Key (solubility values in) (A) buffer, pH 5.0 (B) fed state simulated intestinal fluid, pH 5.0.

Binding of Class I and Class II drugs to albumin when drugs are administered alone (A,B), or together (C). 

For each of the classes of drug to be initiated as secondary prevention state (a) a suitable drug choice and (b) a starting dose. Indicate what clinical trial evidence and national guidelines support the use of the drugs that you have mentioned. 

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