Pharmacology 1 Lecture 8 PDF

PHARMACOLOGY 1 DONE BY LECTURE 8 LAYAN BADER SARA AL-ASMAR EMAN AL-MALAKH B1 selective agonists: Drug: Dobutamine It is B1 selective, so it will be affecting the heart only. Remember: the predominant receptors in the heart are B1 receptors. When they are activated, they increase the he...

PHARMACOLOGY 1 DONE BY LECTURE 8 LAYAN BADER SARA AL-ASMAR EMAN AL-MALAKH B1 selective agonists: Drug: Dobutamine It is B1 selective, so it will be affecting the heart only. Remember: the predominant receptors in the heart are B1 receptors. When they are activated, they increase the heart rate, force of contraction, and the cardiac output. However, Dobutamine increases the cardiac output without increasing the heart rate, oxygen consumption, or the force of contraction. It is used to treat acute heart failure. B2 selective agonists: Remember, when B2 receptors are activated they cause relaxation of the muscles. They are predominant in the bronchus and respiratory system. They are used to treat asthma if administered to the respiratory system, and used to prevent premature labor if administered to the uterus. Can be nasal spray or drops, and are used as nasal decongestants by constricting the blood vessels or mucus membrane. But the problem with these drugs is that when taken at high doses, they will start affecting alpha2 receptors in the CNS. Remember, activation of alpha2 receptors causes effects similar to clonidine, including hypotension. How will they reach the CNS?.‫وجودة معناته إنه بفوت عالدم‬4‫ ا‬6‫نف وقلنا بيعملو إنقباض للشراي‬C‫مهو احنا بنعطي الدوا جوا ا‬ ‫مكنة هو الجهاز‬C‫ ومن هاي ا‬،‫مجرد ما فات عالدم معناته في إحتمال يوصل أي مكان بالجسم‬ ‫ركزي‬4‫العصبي ا‬ Other side effects include headache, decrease in blood pressure, and will stop giving the wanted (decongestant) effect. To prevent these side effects, decongestants are not given on the long term. 1) Very severe decline in blood pressure: To preserve vital signs and maintain stable blood flow to the heart and brain, we treat them with: 1- Norepinephrine Why not epinephrine although it increases systolic blood pressure? Because treatment with epinephrine decreases the diastolic blood pressure as well. In addition, it causes increase in heart rate causing tachycardia in patients with very low blood pressure as in this case. Whereas norepinephrine will not cause these complications, will increase peripheral resistance, and systolic and diastolic blood pressure 2- Phenylephrine Remember, phenylephrine is a alpha1 agonist and causes vasoconstriction —> increase resistance —> increase blood pressure 2) Orthostatic hypotension: 1- Midodrine 3) Emergency treatment of cardiac arrest (complete stoppage of the heart) 1- Isoprotenol We need a drug that is very selective to the heart which is isoprotenol 2- Epinephrine 4) Cardiogenic and septic shock: 1- Dopamine We use dopamine because it has alpha1 and beta agonist effect, which means it increases peripheral resistance, heart rate, blood pressure, and cardiac output. It is also D1 receptor agonist. These receptors are found in arteries that are in the kidneys. Antagonism of these receptors causes vasodilation of these arteries and increases blood flow to the kidneys. This is important to maintain kidney functions in this case of emergency. 5) Acute heart failure 1- Dobutamine This is the only useful agent in this case. It is a beta1 agonist, which means it increases cardiac output without increasing heart rate or oxygen demand Sometimes in some cases we need a local vasoconstriction effect. These cases include: 1) Local anesthesia Example: anesthetic injections before removal of a tooth. Anesthetic injections include adrenaline (epinephrine), which cause vasoconstriction to prevent the spread of the local anesthetic to systemic circulation. Note: epinephrine is not a local anesthetic its self, it is only given with the anesthetic agent. 2) Decongestants The uses are of sympathomimetic drugs in the respiratory system include: 1) Emergency of severe asthmatic shocks 1- Epinephrine This is the main treatment of this case. It causes bronchodilation, decreases release of allergic mediators (histamine from mast cells). 2) Acute asthma 3) Chronic asthma 4) COPDs  drug of choice - There's a condition called anaphylactic shock → a severe allergic reaction ‫اعلى مستوى من الحساسية‬ ‫ لو تعرض عاد الشخص لهاد األكل و صار‬،‫لو حد عنده تحسس من أي نوع من األكل‬ allergy ‫عنده أعراض متل احمرار في منطقة الفم أو حكة في هاي الحالة بنسميها‬ ‫ اكتر من جهاز في الجسم بتأثر ف مثال‬anaphylaxis ‫لكن في حالة ال‬ ‫بصير في احمرار في منطقة الفم مع تأثر التنفس و كمان القلب بتأثر‬ So in anaphylaxis more than one body system is involved · Respiration is affected > - fast and short breaths + broncho constriction Cardiovascular system is also involved- · > Severe hypotension will occur , and tachycardia Anaphylaxis affects multiple body systems at the same time , whereas an allergic reaction usually involves only one body system In this case usual allergy medications don’t work (like antihistamines) but the patient should be given EPINEPHRINE IM for immediate treatment, because anaphylaxis is a life threatening reaction. What does epinephrine do in this case? when it binds to beta 2 it causes bronchodilation Increases blood pressure when binding to beta 1 Inhibits the release of allergy mediators (e.g. histamine) from mast cells  ins 4) & oldj - z Jolig S As we've mentioned before, its used for its mydriatic effect in retina examination And as an ointment / drops for the eyes for people suffering from an allergy or itching in the conjunctiva zu  S ‫هاد الدوا زي ما حكينا انه قبل شوي بينعطى لتأخير الوالدة املبكرة‬ to delay premature birth by causing relaxation for the uterus preventing contractions ‫هدفه األساسي انه يأخر الوالدة املبكرة عشان يعطي وقت اكتر للجنني عشان ينمو‬ This delay in delivery allows more time for the doctors to give corticosteroid drugs to the mother , to help the baby’s lungs to mature. By doing this the risk of neonatal respiratory syndrome is decreased And this syndrome is a condition where a newborn baby has b trouble breathing because of underdeveloped lungs got  > the - prototype > - Hell , ↳ g. elgoal E - Amphetamine, methamphetamine , methylphenidate,modafinil ….. those all are CNS stimulants. Those drugs are synthesised to enter the CNS and causes the release of catecholamines ( specifically norepinephrine and dopamine because they give a stimulant effect on the CNS ) Those drugs are highly abused They’re used by students to be more active ecstasy ‫حبوب‬، ‫متعارف عليها باسم سوقي‬ it gives the effect of pleasure and alertness and reduces appetite. But for their medical use, they are used to treat “ Attention deficient hyperactivity disorder “ ADHD ‫اضطراب فرط الحركة ونقص التركيز‬ So we give them those drugs to increase the catecholamines in the brain, which helps patients (who are usually children)to be more cognitive, which decreases their hyperactivity They’re also used for the treatment of narcolepsy,which is a chronic sleep disorder ‫بنامو بأوقات غير الطبيعي و بشكل متكرر كتير‬ so we give them those drugs to increase their alertness.  & which is an amino acid & Tyramine → is a by product of the metabolism of tyrosine When we eat food rich in tyrosine, it enters the body and is metabolized and gives tyramine ‫وهي مادة مفترض انه الجسم قادر على انه يتخلص منها‬ by monoamine oxidase enzyme( which is found in GIT , liver and brain), which converts tyramine into inactive metabolites. ‫املشكلة بتصير ملا الشخص يكون عم ياخد دوا شغله‬ monoamine oxidase inhibitor ( like antidepressants, and drugs used for the treatment of Parkinson’s disease) is inhibited tyramine‫اذا ً اإلنزيم الي بمنع تراكم ال‬ ‫ في الجسم‬tyramine‫رح يتراكم ال‬ Then the CNS will uptake it ↳ nerve endings (1 8 Uptake [ - Causing what is called “hypertensive crisis “,because it caused sudden release of Catecholamines ‫ف األشخاص الي بياخدو هاي األدوية الزم ينتبهو أنهم يقللو‬ tyrosine ‫كمية األكل الي بحتوي‬  the > - prototype e.