In addition to blocking conduction in nerve axons in the peripheral nervous system, lidocaine has important effects on the central nervous system and cardiovascular system 10,7,8 . After absorption, lidocaine may cause stimulation of the CNS followed by depression and in the cardiovascular system, it acts primarily on the myocardium where it may produce decreases in electrical excitability, conduction rate, and force of contraction 10,7,8 .
Epidural, spinal, paracervical, or pudendal anesthesia may alter the forces of parturition through changes in uterine contractility or maternal expulsive efforts 10 . In one study, paracervical block anesthesia was associated with a decrease in the mean duration of first stage labor and facilitation of cervical dilation 10 . However, spinal and epidural anesthesia have also been reported to prolong the second stage of labor by removing the parturient’s reflex urge to bear down or by interfering with motor function 10 . The use of obstetrical anesthesia may increase the need for forceps assistance 10 .
Structure for Lidocaine (DB00281)
Lidocaine is an anesthetic of the amide group indicated for production of local or regional anesthesia by infiltration techniques such as percutaneous injection and intravenous regional anesthesia by peripheral nerve block techniques such as brachial plexus and intercostal and by central neural techniques such as lumbar and caudal epidural blocks 10,7 .
In general, lidocaine is readily absorbed across mucous membranes and damaged skin but poorly through intact skin 12 . The agent is quickly absorbed from the upper airway, tracheobronchial tree, and alveoli into the bloodstream 12 . And although lidocaine is also well absorbed across the gastrointestinal tract the oral bioavailability is only about 35% as a result of a high degree of first-pass metabolism 12 . After injection into tissues, lidocaine is also rapidly absorbed and the absorption rate is affected by both vascularity and the presence of tissue and fat capable of binding lidocaine in the particular tissues 12 .
Nevertheless, it has been observed that lidocaine hydrochloride is completely absorbed following parenteral administration, its rate of absorption depending also on lipid solubility and the presence or absence of a vasoconstrictor agent 10,7,8 . Except for intravascular administration, the highest blood levels are obtained following intercostal nerve block and the lowest after subcutaneous administration 10,7,8 .
For example, CBD cream may interacts with warfarin. Due to the same interaction with the P450 enzyme pathways, doses of warfarin may need to be decreased in order to prevent any harmful effects. If you are on blood thinners, you need to talk to your doctor 6 .
This is because transdermal patches are direct to the bloodstream and do not get metabolized. This type of CBD delivery method bypasses the digestive tract and liver altogether.
When a topical rubbed on the wrist suddenly causes the skin to become very hot and turn bright red, it is an allergic reaction. Such a reaction might go on its own without any treatment. However, if applied again, it may happen again and start getting worse with time and repetitive applications.
CBD and the Cytochrome P450 Enzyme System
But, with the lack of valid scientific evidence to prove otherwise, it isn’t likely that this topical method of CBD application would cause a drug interaction.
Taking a benzodiazepine (like Valium), for example, and drinking alcohol can cause side effects like confusion, dizziness, sedation, loss of consciousness, and (in severe instances) death. Also, taking blood thinners and eating parsley can make your blood too thin and cause intensive bleeding if you had a cut.
It is true that CBD topicals are not supposed to cause any drug interaction; however, they may cause an allergic reaction.
When certain existing medical conditions make certain drugs potentially harmful.